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AbstractBased on the investigation of 56 soil samples (0-30 cm) in citrus orchards of Guangxi, the content of soil organic matter and available nutrients as well as their correlations in the citrus orchards were studied. The results showed that soil was rich in organic matter, and the proportion of soil samples deficient in available N, P and K was 30.36%, 32.14% and 28.57% respectively. Soil was seriously deficient in soil available Ca, Mg and B, while the content of soil available Fe and Cu in soil was too high. There were significant or extremely significant positive or negative correlations between soil pH, organic matter and several available nutrients. It is recommended to apply Mg fertilizer, B fertilizer, lime or other alkaline fertilizer and reduce the spraying of fungicides containing Cu in the citrus orchards.
Key wordsCitrus orchards; Soil available nutrients; Content; Guangxi
Received: September 14, 2018Accepted: October 31, 2018
Supported by Research and Development Project of Yongning District, Nanning City, Guangxi (20170103B).
Yuyi HUANG (1962-), male, P. R. China, research fellow, devoted to research about soil environmental quality and plant nutrition.
*Corresponding author. Email: 603833188@qq.com.
Guangxi is one of the main producing areas of citrus in China. In 2015, the cultivated area of citrus in Guangxi was 333 000 hm2, and its annual output was 5.193 million t［1］. In order to scientifically guide the rational fertilization of citrus orchards to achieve the purpose of improving citrus yield, improving fruit quality, increasing fruit farmers' economic benefit and improving soil ecological environment of citrus orchards, the author began to investigate soil nutrient fertility of citrus orchards in the main producing area of citrus in Guangxi in 2004. In this study, the content of soil available nutrients in the citrus orchards of Guangxi was analyzed, and the relationship between soil pH, organic matter and available nutrients was discussed.
Materials and Methods
Collection of soil samples
In each citrus orchard in the main producing area of citrus in Guangxi, soil samples (0-30 cm) were collected randomly from several points to mix them into one sample. Sampling was performed by quartering, and 1 kg of each soil sample was left finally. All samples were aired in a room, ground and sieved for use. A total of 56 soil samples were collected. Determination methods
Soil pH was measured by water extraction and potential method (the ratio of soil to water was 1∶2.5). Organic matter was detected by potassium dichromate volumetric method. Available N was measured by 1N NaOH alkaline hydrolysis diffusion method. Available P was detected by Olsen method. Available K was determined by 1N neutral ammonium acetate extraction and flame spectrophotometry. Available Ca and Mg were measured by 1N neutral ammonium acetate extraction and atomic absorption method. Available Fe, Cu, and Zn were determined by DTPA extraction and atomic absorption spectrometry. Available B was measured by hot water extraction and curcumin colorimetric method.
Data processing
The average, coefficient of variation and distribution frequency of soil organic matter and available nutrient content in the citrus orchards were counted, and the correlations between soil pH (or organic matter) and available nutrients were analyzed. The abundance or deficiency of available nutrients were discussed. All statistical analyses were performed using SPSS software.
Results and Analysis
Content of soil available nutrients in the citrus orchards
According to Table 1, the average content of soil organic matter in the citrus orchards was 25.1 g/kg, and the average content of available N, P and K was 122.3, 30.1 and 156.9 mg/kg respectively. There were small differences in soil organic matter and available N and big differences in soil available P and available K. The coefficient of variation of the latter two was 88.2% and 55.6% respectively.
The content of soil available Ca and available Mg in the citrus orchards was analyzed respectively. The results showed that the content of available Ca ranged from 162.1 to 7 550.0 mg/kg and averaged 1 442.3 mg/kg. The content of available Mg varied from 5.7 to 257.4 mg/kg, and the average was 74.9 mg/kg. The coefficient of variation of available Ca and available Mg was 98.5% and 71.1% respectively, revealing that there was a bigger difference in the content of soil available Ca than the content of soil available Mg in the citrus orchards.
The content of soil available microelements in the citrus orchards is shown in Table 2. The average content of available Fe and available Cu was 61.9 and 4.22 mg/kg respectively, while the average content of available Zn and available B was 2.89 and 0.160 mg/kg respectively. There were great changes in the content of soil available microelements in the citrus orchards. Among the microelements, the coefficient of variation of available Cu was the largest, up to 132.5%, followed by available Zn (91.8%). Classification of soil available nutrients in the citrus orchards
Standards for the classification of available nutrients
Soil available nutrients in the citrus orchards were classified according to the standards of previous studies［2-5］. Among them, organic matter content was divided into five grades: extremely low (<5 g/kg), low (5-10 g/kg), lower (10-15 g/kg), adequate (15-30 g/kg), and rich (>30 g/kg). Standards for the classification of other available nutrients are shown in Table 3.
Table 1Content of soil organic matter and available macroelements in the citrus orchards
ItemOrganic matter∥g/kgAvailable N∥mg/kgAvailable P∥mg/kgAvailable K∥mg/kg
Range11.5-43.859.7-189.64.1-151.228.7-448.4
Average25.1122.330.1156.9
Coefficient of variation∥%29.325.688.255.6
Table 2Content of available microelements in the citrus orchardsmg/kg
ItemAvailable FeAvailable CuAvailable ZnAvailable B
Range11.9-247.80.38-22.410.12-14.430.016-0.400
Average61.94.222.890.160
Coefficient of variation∥%87.7132.5091.8048.100
Table 3Standards for classification of soil available nutrients in the citrus orchardsmg/kg
Available nutrientExtremely deficientDeficientModerateHighExcessive
Available N<5050-100100-200>200-
Available P<505-1515-80>80-
Available K<5050-100100-200>200-
Available Ca<200200-1 0001 000-2 0002 000-3 000>3 000
Available Mg<8080-150150-300300-500>500
Available Fe<55-1010-2020-50>50
Available Cu<0.30.3-0.50.5-1.01.0-2.0>2.0
Available Zn<0.50.5-0.11.0-5.05.0-10.0>10.0
Available B<0.250.25-0.500.50-1.001.00-2.00>2.00
Organic matter
In the citrus orchards of Guangxi, soil was rich in organic matter, and organic matter content was higher than 15 g/kg in 89.28% of soil samples, of which it was higher than 30 g/kg in 19.64% of soil samples. It was lower in 10.72% of soil samples, and there was no soil with extremely low or low content of organic matter.
Available nutrients
According to Table 4, the number of soil samples with moderate contents of available N, P and K accounted for 69.64%, 62.50% and 42.86% of total number of soil samples respectively. The proportion of soil samples with high contents of available N, P and K was 0, 5.36% and 28.57% respectively. The number of soil samples with moderate contents of available Ca and Mg accounted for 48.21% and 7.14% of total number of soil samples respectively, while the number of soil samples deficient in available Ca and Mg accounted for 51.79% and 92.86% respectively. The proportion of soil samples containing excessive available Fe and Cu was high. Most of soil samples were deficient in available Zn and B, of which the deficient of available B was very serious. The content of available Fe and Cu was high and excessive in 87.50% and 76.78% of soil samples respectively. 19.64% and 100.00% of soil samples were deficient in available Zn and B respectively. Table 4Percentage of soil samples with different levels of soil available nutrients in the citrus orchards%
Available nutrientExtremely deficientDeficientModerateHighExcessive
Available N030.3669.640-
Available P3.5728.5762.505.36-
Available K7.1421.4342.8628.57-
Available Ca3.5748.2232.143.5712.50
Available Mg58.9333.937.1400
Available Fe0012.5044.6442.86
Available Cu05.3617.8625.0051.78
Available Zn5.3614.2867.8610.711.79
Available B87.5012.50000
Relationship between soil pH, organic matter and available nutrients
In the citrus orchards, soil pH ranged from 3.60 to 8.12, and it was lower than 5.5 in 66.07% of the citrus orchards. Seen from Table 5, there was an extremely significant positive correlation between soil pH and available Ca and Mg and a significant negative correlation between soil pH and available Fe. There was
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Agricultural Biotechnology2019, 8（1）: 152-155
Forestry Science
Qiong MOU et al. Planting Adaptability of Brassica napobrassica cv. Huaxi Under Economic Fruit Forest
Planting Adaptability of Brassica napobrassica cv. Huaxi Under Economic Fruit Forest
Qiong MOU1,2, Chengjiang PEI1, Jiahai WU1*, Yousong WU3, Juan LI1, Kongzhen LENG4, Weinan RAN1
1. Guizhou Pratacultural Institute, Guizhou Academy of Agricultural Sciences, Guiyang 550006, China;
2. Guizhou Jinnongfuping Ecological Agriculture and Animal Husbandry Science and Technology Co., Ltd., Songtao 554100, China; 3. Songtao Bureau of Animal Husbandry, Songtao 554100, China; 4. Daozhen Bureau of Animal Husbandry, Daozhen 563500, China
AbstractThe growth speed, fresh grass yield, nutritional components, soil nutrient variation and economic benefit of Brassica napobrassica cv. Huaxi under different planting patterns (drilling, hole sowing and seedling transplanting) were analyzed by a test of interplanting B. napobrassica cv. Huaxi under economic fruit forest, to solve the contradiction between food and feed during rapid development of ecological animal husbandry and improve land utilization rate. The comprehensive performance of B. napobrassica cv. Huaxi was good under the three planting patterns, and the comprehensive performance of B. napobrassica cv. Huaxi under the seedling transplanting pattern was the best among the three planting patterns. The fresh grass yield and net profit of B. napobrassica cv. Huaxi under the seedling transplanting pattern can reach 125 580.0 kg/hm2 and 16 674.0 Yuan/hm2, respectively. Interplanting B. napobrassica cv. Huaxi under economic fruit forest can improve soil physical and chemical properties, increase soil nutrients and inhibit weed growth. Key wordsBrassica napobrassica cv. Huaxi; Economic fruit forest; Planting pattern; Pasture
Received: June 16, 2018Accepted: September 24, 2018
Supported by Major Project of Guizhou Science and Technology Agency［QKHZDZXZ (2014)6017］; Guizhou Highlevel Innovative Talent Training Project［QKHPTRC(2016)5713］; Guizhou Highlevel Innovative Talent Training Project［QKHRC(2016)4024］; "Integrated Application of Matching Techniques for Pasture Industry in Wuling Mountainous Area"［QKHCG(2016)4042］.
Qiong MOU (1970-), female, P. R. China, researcher, devoted to research about forage breeding and utilization.
*Corresponding author. Email: 184826618@qq.com.
In the development process of grassland ecological animal husbandry in Guizhou Province, there is a longterm phenomenon of highquality green succulent feed shortage. Interplanting highquality forage grass in the dormant period of fruit trees to solve the contradiction between food and feed during rapid development of ecological animal husbandry and improve land utilization rate has become a hot research topic. During the "13th FiveYear Plan" period, the total area of fruit trees in Guizhou Province is estimated to be 1.67 million hm2 or more［1］. There is a certain amount of free land and space in fruit tree forests, and especially, more free land and space in newly planted young forests. Intercropping suitable crops will greatly improve economic efficiency. Brassica napobrassica cv. Huaxi is a new forage species bred by the Guizhou Pratacultural Institute［2］, which was approved by the National Grass Variety Examination and Approval Committee (Guoshencao No. 472) in 2014. This variety has short growth period, high yield and resistance, excellent comprehensive traits, etc., and is suitable for popularization in the vast agricultural areas of Guizhou Province［3］. In order to accelerate the promotion of this variety and give play to its unique role in the adjustment of crop farming structure, different planting patterns of B. napobrassica cv. Huaxi under fruit forest were studied, so as to make full use of the dormant period of fruit forest and vigorously develop the combination model of fruit and forage.
Materials and Methods
Basic situation of experimental field
The experiment was carried out in Baiguo Village, Taipingying Township, Songtao Miao Autonomous County, Tongren City, Guizhou Province, at N28°17′, E109°18′, with an altitude of 690 m, which has a subtropical monsoon climate. The area has a mild climate with enough sunshine and abundant rainfall. The annual average temperature is 16.3 ℃ and the annual precipitation is 1 047 mm. The average relative humidity is 82%. Experimental materials
The experimental forage variety was B. napobrassica cv. Huaxi, which was provided by the Guizhou Pratacultural Institute. The tested fruit forest was a prosperous vineyard.
Experimental design
The experiment used B. napobrassica cv. Huaxi as the planting object and was designed with three treatments. Treatment 1 was hole sowing with a seeding rate at 9 kg/hm2 and a plant spacing of 40 cm×50 cm; treatment 2 was drilling with a seeding rate at 9 kg/hm2, and a row spacing of 50 cm; and treatment 3 was seedling transplanting, under which the seeding rate was calculated according to 4.5 kg/hm2, and the transplanting spacing was 40 cm×50 cm. Each treatment had an average area of 1 hm2, and the total area was 3 hm2.
Experimental process
There were many weeds in the fruit forest, including annual common weeds and perennial thatch with deep roots and many leaves, and the soil was harder. The weeds were removed manually, and the land was ploughed and leveled. For the various treatments, sowing was performed on September 11, 2014, and seedlings emerged 2-3 d after sowing. Reseeding was performed timely according to the emergence of seedlings. Thinning was performed once when the seedlings had 1 to 2 leaves and 3 to 4 leaves, respectively, and final singling was performed at the stage of 5-6 leaves. Fertilizer for protecting seedlings was applied after emergence and before final singling appropriately, a small amount of fertilizer was applied when the seedlings had two true leaves, and weeding and topdressing were performed after the second time of thinning. The second time of topdressing was performed after scarified stage and before shoulder exposing stage. During topdressing, fertilizer should not be applied near the fleshy root; and intertillage should be carried out according to the principles of deep at first and shallow then, near at first and far then, and stopped after closing of crop［4］.
Determined indices
In the vegetative growth period of B. napobrassica cv. Huaxi, 9 quadrats (1 m×1 m) were selected in each test group every 15 d, for the determination of growth and adaptability of B. napobrassica cv. Huaxi, including plant height, leaf number, leaf length, root length and root diameter, weight of aboveground part, weight of underground part and fresh grass yield. Nutritional components (moisture, crude protein, crude fat, crude fiber, nitrogenfree extract, crude ash, Ca and P) were determined according to GB/T 64321994 Method for the determination of crude protein in feedstuffs, GB/T64342006 Method for the determination of crude fiber in feedstuffs , GB/T64332006 Method for the determination of crude fat in feedstuffs, GB/T64351986 Method for the determination of moisture in feedstuffs and GB/T64382007 Method for the determination of crude ash in feedstuffs. Results and Analysis
Growth dynamic of B. napobrassica cv. Huaxi planted under fruit forest by different methods
B. napobrassica cv. Huaxi was planted under the fruit forest. For all the three planting methods, seedlings emerged 2-3 d after sowing, and reached full stand at about 10 d. It could be seen from Table 1 that B. napobrassica cv. Huaxi planted by different methods all could adapt to the climatic condition in the experimental area and grew well in vegetative growth phase. The aboveground organ grew faster before November 20, and slower then, while the growth of the underground organ was accelerated after mid November. Among the three treatments, treatment 3 showed various organs grown faster, and until January 1 of the next year, treatment 3 performed better in plant height, leaf length, leaf width, root length and root diameter, which were 41.28, 46.44, 16.6, 26.66 and 13.93 cm, respectively, suggesting that seedling transplanting is the best for plantation of B. napobrassica cv. Huaxi under fruit forests.
Table 1Growth dynamic of B. napobrassica cv. Huaxi at different growth stages during 2014-2015
TreatmentItem
Investigation date
Sept. 20Oct. 5Oct. 20Nov. 5Nov. 20 Dec. 5Dec. 20Jan. 5
1Plant height∥cm 2.9318.3828.7333.3834.8835.435.6336.0
Leaf number∥leaves 2.005.0010.0012.00 15.0017.0017.0018.00
Leaf length∥cm3.8318.0027.0033.7539.7540.1340.1340.50
Leaf width∥cm 2.259.1512.7513.8814.2514.4014.4014.48
Root length∥cm- 13.1318.7520.1821.2321.7522.0523.25
Root diameter∥cm - 1.502.635.038.8510.511.3312.15
2Plant height∥cm 3.1219.6030.6435.6037.2037.7638.0038.40
Leaf number∥leaves 2.005.0010.0012.0015.0017.0017.0018.00
Leaf length∥cm4.0819.2028.8036.0042.4042.8042.8043.20
Leaf width∥cm 2.409.7613.6014.8015.2015.3615.3615.44
Root length∥cm- 14.0020.0021.5222.6423.2023.5224.80
Root diameter∥cm - 1.602.805.369.4411.2012.0812.96
3Plant height∥cm 3.3521.0732.9438.2739.9940.5940.8541.28
Leaf number∥leaves 2.005.0010.0012.00 15.0017.0017.0018.00
Leaf length∥cm4.3920.6430.9638.7045.5846.0146.0146.44
Leaf width∥cm 2.5810.4914.6215.9116.3416.5116.5116.60
Root length∥cm- 15.0521.5023.1324.3424.9425.2826.66
Root diameter∥cm - 1.723.015.7610.1512.0412.9913.93
Yields of B. napobrassica cv. Huaxi planted under fruit forest by different methods It could be seen from Table 2 that under the same management level, various treatments differed in stem and leaf yield and root yield. The weights of the aboveground and underground parts both ranked as treatment 3＞treatment 2＞treatment 1. Until January 5 of the next year, treatment 3 showed the weight of whole plant up to 2.09 kg/plant. The results of multiple comparison showed that there were no significant differences between treatments 1 and 2 and between treatments 2 and 3 in yield (P＞0.05), while treatment 1 was significantly different treatment 3 (P＜0.05).
Nutritional components of B. napobrassica cv. Huaxi planted under fruit forest by different methods
It could be seen from Table 3 that B. napobrassica cv. Huaxi in treatment 3 had the highest contents of nutritional components, but variance analysis showed that there were no significant differences between various treatments in contents of nutritional components (P＞0.05). It was indicated that different planting methods caused no significant differences in contents of nutritional components of B. napobrassica cv. Huaxi in fruit forest.
Table 2Growth dynamic of biomass of B. napobrassica cv. Huaxi during different growth stages during 2014-2015kg/plant
TreatmentItem
Investigation date
Sept. 20Oct. 5Oct. 20Nov. 5Nov. 20 Dec. 5Dec. 20Jan. 5
1Weight of aboveground part0.030.080.230.310.360.410.400.37
Weight of underground part-0.030.130.240.520.991.141.30
Weight of whole plant 0.030.100.360.560.881.391.541.67
2Weight of aboveground part0.030.090.260.350.400.450.450.42
Weight of underground part- 0.030.150.270.581.101.281.45
Weight of whole plant 0.030.120.400.620.981.551.721.87
3Weight of aboveground part0.030.100.290.390.450.510.500.47
Weight of underground part- 0.030.160.310.651.241.431.63
Weight of whole plant 0.030.130.450.701.101.741.932.09
Table 3Nutritional components of B. napobrassica cv. Huaxi under different planting patterns%
Treatment Moisture Crude protein Crude fat Crude fiber Nitrogenfree extract Crude ash CaP
189.341.4350.2480.9027.4980.4970.0360.044
288.411.5600.2700.9808.1500.5400.0390.048
387.831.6380.2841.0298.5580.5670.0410.050
Agricultural Biotechnology2019
Economic benefit of B. napobrassica cv. Huaxi planted under fruit forest by different methods
It could be seen from Table 4 that the economic benefit of treatments 1, 2 and 3 were 10 639.2, 14 116.8 and 16 674.0 Yuan/hm2, among which treatment 3 had the highest economic benefit, suggesting that treatment 3 could improve economic benefit for farmers. The results of multiple comparison showed that there were no significant differences between treatments 1 and 2 and between treatments 2 and 3 (P＞0.05), and there was a significant difference between treatments 3 and 1 (P＜0.05). Table 4Economic benefit of B. napobrassica cv. Huaxi under different planting patterns
Treatment Planting patternGrowth period∥dYield∥kg/hm2Output value∥Yuan/hm2Cost∥Yuan/hm2Net profit∥Yuan/hm2
1Hole sowing 122100 464.030 139.219 500.010 639.2
2drilling122112 056.033 616.819 500.014 116.8
3Seedling planting 122125 580.037 674.021 000.016 674.0
Variations of soil nutrients caused by planting B. napobrassica cv. Huaxi under fruit forest
It could be seen from Table 5 that after interplanting B. napobrassica cv. Huaxi under fruit forest, soil organic matter content and soil nutrient contents were improved to different degrees compared with the CK (soil under fruit forest, not planted with B. napobrassica cv. Huaxi). Among the various treatments, treatment 3 had the highest organic matter content, and its total N and total K contents were improved at the highest proportions. The three treatments had no significant differences in available nutrients and effective nutrients. It was indicated that interplanting B. napobrassica cv. Huaxi under fruit forest could improve soil physical and chemical properties and soil organic matter and nutrient contents to different degrees, thereby promoting growth of fruit forest as well as improving fruit quality.
Table 5Soil nutrients of planting B. napobrassica cv. Huaxi under fruit forest
Treatment pHOrganic matterg/kg
Total nutrient∥%
NP2O5K2O
Available nutrient∥mg/kg
NP2O5K2O
Effective nutrient∥mg/kg
CuZnFeMn
CK5.1013.800.1240.0250.672923770.550.5716.701.65
15.2017.010.1530.0210.71110511060.610.7349.315.30
25.0816.300.1480.0270.72511421080.590.7750.335.50
35.2217.500.1660.0260.75310821060.600.7151.205.01
Conclusions and Discussion
The results of this study showed that B. napobrassica cv. Huaxi could well adapt to soil and climatic conditions under fruit forest, and the crop and the fruit trees both could grow well. Among the three planting patterns (drilling, hole sowing and seedling transplanting) for B. napobrassica cv. Huaxi under fruit forest, seedling transplanting performed the best, achieved high fresh grass yield (125 580.0 kg/hm2) and better economic benefit (pure profit reaching 16 674.0 yuan/hm2), and could better improve soil physical and chemical properties and soil nutrient contents under fruit forest.
Compared with conventional clean tillage, interplanting forage under fruit trees could improve cropping index of unit area［5］, and could take full advantage of water and fertilizer under fruit forest to promote growth of fruit trees and improve yield and quality of fruit［6］. This method also could achieve the effects of improving soil fertility［7］, effectively improving microclimate in orchard［8］, reducing ground temperature and air temperature［9］, reducing environmental pollution, inhibiting road dust［10］, and significantly improving economic benefit, social benefit and ecological benefit. B. napobrassica cv. Huaxi has the advantages of good palatability, high yield, short production cycle and easy storage, and is favored by animals. It is a highquality green and juicy feed source for cattle, sheep and other animals. Interplanting B. napobrassica cv. Huaxi in orchard is simple in operation, easy to manage, harvest, store and use, and has high economic benefit. It can be further popularized and applied in production to realize the adjustment of agricultural industrial structure in povertystricken areas and increase farmers income.
References
［1］ ZHU XT. Highyield cultivation technique of interplanting soybean in economic fruit forest in mountainous region in Guizhou Province［J］. Soybean Bulletin, 2017(3): 33-38.
［2］ WANG YF. Effect of different chemical application level on seed yield of Brassica hapobrassica in Huaxi［J］. Southwest China Journal of Agricultural Sciences, 2016, 29(4): 842-846.
［3］ YANG YC, MOU Q, WANG YF, et al. Study on adaptability of Huaxi gray radish in cold highland are of northwestern Guizhou［J］. Heilongjiang Animal Science and Veterinary Medicine, 2013(5): 73-75.
［4］ MOU Q. Production test of gray radish in Huaxi［J］. Pratacultural Science, 2013, 30(6): 910-914.
［5］ LAI ZQ. Revitalization and recultivation of vegetation in Karst region through animal［J］. Pratacultural Science, 2008, 25(9): 103-108.
［6］ YU LH. Study on the cover technology for the overwintering of highquality orchard grasses in Beijing［J］.Pratacultural Science, 2009, 26(6): 166-171.
［7］ DONG SQ. Effects on interplanting forage in orchid on ecological environment and culture fertility［J］. Mod Agric Sci Technol, 2006(12): 11-12.
［8］ LI HK, ZHENG QL, ZHAO ZY, et al. Study on the root system distribution characteristics of several herbage species growing in apple orchard in loess plateau［J］. Pratacultural Science, 2008, 17(2): 92-96.
［9］ GU YR, ZHANG HL, HU YH, et al. Effect of natural grasses cover on soil properties and yield and quality of peach［J］. Pratacultural Science, 2009, 26(12): 103-107.
［10］ MENG L, YU LH, MAO PC, et al. Effects of Interplanting cocksfoot and white clover as cover crops on the microclimate of apple orchard［J］. Pratacultural Science, 2009, 26(8): 132-136.
Key wordsCitrus orchards; Soil available nutrients; Content; Guangxi
Received: September 14, 2018Accepted: October 31, 2018
Supported by Research and Development Project of Yongning District, Nanning City, Guangxi (20170103B).
Yuyi HUANG (1962-), male, P. R. China, research fellow, devoted to research about soil environmental quality and plant nutrition.
*Corresponding author. Email: 603833188@qq.com.
Guangxi is one of the main producing areas of citrus in China. In 2015, the cultivated area of citrus in Guangxi was 333 000 hm2, and its annual output was 5.193 million t［1］. In order to scientifically guide the rational fertilization of citrus orchards to achieve the purpose of improving citrus yield, improving fruit quality, increasing fruit farmers' economic benefit and improving soil ecological environment of citrus orchards, the author began to investigate soil nutrient fertility of citrus orchards in the main producing area of citrus in Guangxi in 2004. In this study, the content of soil available nutrients in the citrus orchards of Guangxi was analyzed, and the relationship between soil pH, organic matter and available nutrients was discussed.
Materials and Methods
Collection of soil samples
In each citrus orchard in the main producing area of citrus in Guangxi, soil samples (0-30 cm) were collected randomly from several points to mix them into one sample. Sampling was performed by quartering, and 1 kg of each soil sample was left finally. All samples were aired in a room, ground and sieved for use. A total of 56 soil samples were collected. Determination methods
Soil pH was measured by water extraction and potential method (the ratio of soil to water was 1∶2.5). Organic matter was detected by potassium dichromate volumetric method. Available N was measured by 1N NaOH alkaline hydrolysis diffusion method. Available P was detected by Olsen method. Available K was determined by 1N neutral ammonium acetate extraction and flame spectrophotometry. Available Ca and Mg were measured by 1N neutral ammonium acetate extraction and atomic absorption method. Available Fe, Cu, and Zn were determined by DTPA extraction and atomic absorption spectrometry. Available B was measured by hot water extraction and curcumin colorimetric method.
Data processing
The average, coefficient of variation and distribution frequency of soil organic matter and available nutrient content in the citrus orchards were counted, and the correlations between soil pH (or organic matter) and available nutrients were analyzed. The abundance or deficiency of available nutrients were discussed. All statistical analyses were performed using SPSS software.
Results and Analysis
Content of soil available nutrients in the citrus orchards
According to Table 1, the average content of soil organic matter in the citrus orchards was 25.1 g/kg, and the average content of available N, P and K was 122.3, 30.1 and 156.9 mg/kg respectively. There were small differences in soil organic matter and available N and big differences in soil available P and available K. The coefficient of variation of the latter two was 88.2% and 55.6% respectively.
The content of soil available Ca and available Mg in the citrus orchards was analyzed respectively. The results showed that the content of available Ca ranged from 162.1 to 7 550.0 mg/kg and averaged 1 442.3 mg/kg. The content of available Mg varied from 5.7 to 257.4 mg/kg, and the average was 74.9 mg/kg. The coefficient of variation of available Ca and available Mg was 98.5% and 71.1% respectively, revealing that there was a bigger difference in the content of soil available Ca than the content of soil available Mg in the citrus orchards.
The content of soil available microelements in the citrus orchards is shown in Table 2. The average content of available Fe and available Cu was 61.9 and 4.22 mg/kg respectively, while the average content of available Zn and available B was 2.89 and 0.160 mg/kg respectively. There were great changes in the content of soil available microelements in the citrus orchards. Among the microelements, the coefficient of variation of available Cu was the largest, up to 132.5%, followed by available Zn (91.8%). Classification of soil available nutrients in the citrus orchards
Standards for the classification of available nutrients
Soil available nutrients in the citrus orchards were classified according to the standards of previous studies［2-5］. Among them, organic matter content was divided into five grades: extremely low (<5 g/kg), low (5-10 g/kg), lower (10-15 g/kg), adequate (15-30 g/kg), and rich (>30 g/kg). Standards for the classification of other available nutrients are shown in Table 3.
Table 1Content of soil organic matter and available macroelements in the citrus orchards
ItemOrganic matter∥g/kgAvailable N∥mg/kgAvailable P∥mg/kgAvailable K∥mg/kg
Range11.5-43.859.7-189.64.1-151.228.7-448.4
Average25.1122.330.1156.9
Coefficient of variation∥%29.325.688.255.6
Table 2Content of available microelements in the citrus orchardsmg/kg
ItemAvailable FeAvailable CuAvailable ZnAvailable B
Range11.9-247.80.38-22.410.12-14.430.016-0.400
Average61.94.222.890.160
Coefficient of variation∥%87.7132.5091.8048.100
Table 3Standards for classification of soil available nutrients in the citrus orchardsmg/kg
Available nutrientExtremely deficientDeficientModerateHighExcessive
Available N<5050-100100-200>200-
Available P<505-1515-80>80-
Available K<5050-100100-200>200-
Available Ca<200200-1 0001 000-2 0002 000-3 000>3 000
Available Mg<8080-150150-300300-500>500
Available Fe<55-1010-2020-50>50
Available Cu<0.30.3-0.50.5-1.01.0-2.0>2.0
Available Zn<0.50.5-0.11.0-5.05.0-10.0>10.0
Available B<0.250.25-0.500.50-1.001.00-2.00>2.00
Organic matter
In the citrus orchards of Guangxi, soil was rich in organic matter, and organic matter content was higher than 15 g/kg in 89.28% of soil samples, of which it was higher than 30 g/kg in 19.64% of soil samples. It was lower in 10.72% of soil samples, and there was no soil with extremely low or low content of organic matter.
Available nutrients
According to Table 4, the number of soil samples with moderate contents of available N, P and K accounted for 69.64%, 62.50% and 42.86% of total number of soil samples respectively. The proportion of soil samples with high contents of available N, P and K was 0, 5.36% and 28.57% respectively. The number of soil samples with moderate contents of available Ca and Mg accounted for 48.21% and 7.14% of total number of soil samples respectively, while the number of soil samples deficient in available Ca and Mg accounted for 51.79% and 92.86% respectively. The proportion of soil samples containing excessive available Fe and Cu was high. Most of soil samples were deficient in available Zn and B, of which the deficient of available B was very serious. The content of available Fe and Cu was high and excessive in 87.50% and 76.78% of soil samples respectively. 19.64% and 100.00% of soil samples were deficient in available Zn and B respectively. Table 4Percentage of soil samples with different levels of soil available nutrients in the citrus orchards%
Available nutrientExtremely deficientDeficientModerateHighExcessive
Available N030.3669.640-
Available P3.5728.5762.505.36-
Available K7.1421.4342.8628.57-
Available Ca3.5748.2232.143.5712.50
Available Mg58.9333.937.1400
Available Fe0012.5044.6442.86
Available Cu05.3617.8625.0051.78
Available Zn5.3614.2867.8610.711.79
Available B87.5012.50000
Relationship between soil pH, organic matter and available nutrients
In the citrus orchards, soil pH ranged from 3.60 to 8.12, and it was lower than 5.5 in 66.07% of the citrus orchards. Seen from Table 5, there was an extremely significant positive correlation between soil pH and available Ca and Mg and a significant negative correlation between soil pH and available Fe. There was
(Continued on page 155)
Agricultural Biotechnology2019, 8（1）: 152-155
Forestry Science
Qiong MOU et al. Planting Adaptability of Brassica napobrassica cv. Huaxi Under Economic Fruit Forest
Planting Adaptability of Brassica napobrassica cv. Huaxi Under Economic Fruit Forest
Qiong MOU1,2, Chengjiang PEI1, Jiahai WU1*, Yousong WU3, Juan LI1, Kongzhen LENG4, Weinan RAN1
1. Guizhou Pratacultural Institute, Guizhou Academy of Agricultural Sciences, Guiyang 550006, China;
2. Guizhou Jinnongfuping Ecological Agriculture and Animal Husbandry Science and Technology Co., Ltd., Songtao 554100, China; 3. Songtao Bureau of Animal Husbandry, Songtao 554100, China; 4. Daozhen Bureau of Animal Husbandry, Daozhen 563500, China
AbstractThe growth speed, fresh grass yield, nutritional components, soil nutrient variation and economic benefit of Brassica napobrassica cv. Huaxi under different planting patterns (drilling, hole sowing and seedling transplanting) were analyzed by a test of interplanting B. napobrassica cv. Huaxi under economic fruit forest, to solve the contradiction between food and feed during rapid development of ecological animal husbandry and improve land utilization rate. The comprehensive performance of B. napobrassica cv. Huaxi was good under the three planting patterns, and the comprehensive performance of B. napobrassica cv. Huaxi under the seedling transplanting pattern was the best among the three planting patterns. The fresh grass yield and net profit of B. napobrassica cv. Huaxi under the seedling transplanting pattern can reach 125 580.0 kg/hm2 and 16 674.0 Yuan/hm2, respectively. Interplanting B. napobrassica cv. Huaxi under economic fruit forest can improve soil physical and chemical properties, increase soil nutrients and inhibit weed growth. Key wordsBrassica napobrassica cv. Huaxi; Economic fruit forest; Planting pattern; Pasture
Received: June 16, 2018Accepted: September 24, 2018
Supported by Major Project of Guizhou Science and Technology Agency［QKHZDZXZ (2014)6017］; Guizhou Highlevel Innovative Talent Training Project［QKHPTRC(2016)5713］; Guizhou Highlevel Innovative Talent Training Project［QKHRC(2016)4024］; "Integrated Application of Matching Techniques for Pasture Industry in Wuling Mountainous Area"［QKHCG(2016)4042］.
Qiong MOU (1970-), female, P. R. China, researcher, devoted to research about forage breeding and utilization.
*Corresponding author. Email: 184826618@qq.com.
In the development process of grassland ecological animal husbandry in Guizhou Province, there is a longterm phenomenon of highquality green succulent feed shortage. Interplanting highquality forage grass in the dormant period of fruit trees to solve the contradiction between food and feed during rapid development of ecological animal husbandry and improve land utilization rate has become a hot research topic. During the "13th FiveYear Plan" period, the total area of fruit trees in Guizhou Province is estimated to be 1.67 million hm2 or more［1］. There is a certain amount of free land and space in fruit tree forests, and especially, more free land and space in newly planted young forests. Intercropping suitable crops will greatly improve economic efficiency. Brassica napobrassica cv. Huaxi is a new forage species bred by the Guizhou Pratacultural Institute［2］, which was approved by the National Grass Variety Examination and Approval Committee (Guoshencao No. 472) in 2014. This variety has short growth period, high yield and resistance, excellent comprehensive traits, etc., and is suitable for popularization in the vast agricultural areas of Guizhou Province［3］. In order to accelerate the promotion of this variety and give play to its unique role in the adjustment of crop farming structure, different planting patterns of B. napobrassica cv. Huaxi under fruit forest were studied, so as to make full use of the dormant period of fruit forest and vigorously develop the combination model of fruit and forage.
Materials and Methods
Basic situation of experimental field
The experiment was carried out in Baiguo Village, Taipingying Township, Songtao Miao Autonomous County, Tongren City, Guizhou Province, at N28°17′, E109°18′, with an altitude of 690 m, which has a subtropical monsoon climate. The area has a mild climate with enough sunshine and abundant rainfall. The annual average temperature is 16.3 ℃ and the annual precipitation is 1 047 mm. The average relative humidity is 82%. Experimental materials
The experimental forage variety was B. napobrassica cv. Huaxi, which was provided by the Guizhou Pratacultural Institute. The tested fruit forest was a prosperous vineyard.
Experimental design
The experiment used B. napobrassica cv. Huaxi as the planting object and was designed with three treatments. Treatment 1 was hole sowing with a seeding rate at 9 kg/hm2 and a plant spacing of 40 cm×50 cm; treatment 2 was drilling with a seeding rate at 9 kg/hm2, and a row spacing of 50 cm; and treatment 3 was seedling transplanting, under which the seeding rate was calculated according to 4.5 kg/hm2, and the transplanting spacing was 40 cm×50 cm. Each treatment had an average area of 1 hm2, and the total area was 3 hm2.
Experimental process
There were many weeds in the fruit forest, including annual common weeds and perennial thatch with deep roots and many leaves, and the soil was harder. The weeds were removed manually, and the land was ploughed and leveled. For the various treatments, sowing was performed on September 11, 2014, and seedlings emerged 2-3 d after sowing. Reseeding was performed timely according to the emergence of seedlings. Thinning was performed once when the seedlings had 1 to 2 leaves and 3 to 4 leaves, respectively, and final singling was performed at the stage of 5-6 leaves. Fertilizer for protecting seedlings was applied after emergence and before final singling appropriately, a small amount of fertilizer was applied when the seedlings had two true leaves, and weeding and topdressing were performed after the second time of thinning. The second time of topdressing was performed after scarified stage and before shoulder exposing stage. During topdressing, fertilizer should not be applied near the fleshy root; and intertillage should be carried out according to the principles of deep at first and shallow then, near at first and far then, and stopped after closing of crop［4］.
Determined indices
In the vegetative growth period of B. napobrassica cv. Huaxi, 9 quadrats (1 m×1 m) were selected in each test group every 15 d, for the determination of growth and adaptability of B. napobrassica cv. Huaxi, including plant height, leaf number, leaf length, root length and root diameter, weight of aboveground part, weight of underground part and fresh grass yield. Nutritional components (moisture, crude protein, crude fat, crude fiber, nitrogenfree extract, crude ash, Ca and P) were determined according to GB/T 64321994 Method for the determination of crude protein in feedstuffs, GB/T64342006 Method for the determination of crude fiber in feedstuffs , GB/T64332006 Method for the determination of crude fat in feedstuffs, GB/T64351986 Method for the determination of moisture in feedstuffs and GB/T64382007 Method for the determination of crude ash in feedstuffs. Results and Analysis
Growth dynamic of B. napobrassica cv. Huaxi planted under fruit forest by different methods
B. napobrassica cv. Huaxi was planted under the fruit forest. For all the three planting methods, seedlings emerged 2-3 d after sowing, and reached full stand at about 10 d. It could be seen from Table 1 that B. napobrassica cv. Huaxi planted by different methods all could adapt to the climatic condition in the experimental area and grew well in vegetative growth phase. The aboveground organ grew faster before November 20, and slower then, while the growth of the underground organ was accelerated after mid November. Among the three treatments, treatment 3 showed various organs grown faster, and until January 1 of the next year, treatment 3 performed better in plant height, leaf length, leaf width, root length and root diameter, which were 41.28, 46.44, 16.6, 26.66 and 13.93 cm, respectively, suggesting that seedling transplanting is the best for plantation of B. napobrassica cv. Huaxi under fruit forests.
Table 1Growth dynamic of B. napobrassica cv. Huaxi at different growth stages during 2014-2015
TreatmentItem
Investigation date
Sept. 20Oct. 5Oct. 20Nov. 5Nov. 20 Dec. 5Dec. 20Jan. 5
1Plant height∥cm 2.9318.3828.7333.3834.8835.435.6336.0
Leaf number∥leaves 2.005.0010.0012.00 15.0017.0017.0018.00
Leaf length∥cm3.8318.0027.0033.7539.7540.1340.1340.50
Leaf width∥cm 2.259.1512.7513.8814.2514.4014.4014.48
Root length∥cm- 13.1318.7520.1821.2321.7522.0523.25
Root diameter∥cm - 1.502.635.038.8510.511.3312.15
2Plant height∥cm 3.1219.6030.6435.6037.2037.7638.0038.40
Leaf number∥leaves 2.005.0010.0012.0015.0017.0017.0018.00
Leaf length∥cm4.0819.2028.8036.0042.4042.8042.8043.20
Leaf width∥cm 2.409.7613.6014.8015.2015.3615.3615.44
Root length∥cm- 14.0020.0021.5222.6423.2023.5224.80
Root diameter∥cm - 1.602.805.369.4411.2012.0812.96
3Plant height∥cm 3.3521.0732.9438.2739.9940.5940.8541.28
Leaf number∥leaves 2.005.0010.0012.00 15.0017.0017.0018.00
Leaf length∥cm4.3920.6430.9638.7045.5846.0146.0146.44
Leaf width∥cm 2.5810.4914.6215.9116.3416.5116.5116.60
Root length∥cm- 15.0521.5023.1324.3424.9425.2826.66
Root diameter∥cm - 1.723.015.7610.1512.0412.9913.93
Yields of B. napobrassica cv. Huaxi planted under fruit forest by different methods It could be seen from Table 2 that under the same management level, various treatments differed in stem and leaf yield and root yield. The weights of the aboveground and underground parts both ranked as treatment 3＞treatment 2＞treatment 1. Until January 5 of the next year, treatment 3 showed the weight of whole plant up to 2.09 kg/plant. The results of multiple comparison showed that there were no significant differences between treatments 1 and 2 and between treatments 2 and 3 in yield (P＞0.05), while treatment 1 was significantly different treatment 3 (P＜0.05).
Nutritional components of B. napobrassica cv. Huaxi planted under fruit forest by different methods
It could be seen from Table 3 that B. napobrassica cv. Huaxi in treatment 3 had the highest contents of nutritional components, but variance analysis showed that there were no significant differences between various treatments in contents of nutritional components (P＞0.05). It was indicated that different planting methods caused no significant differences in contents of nutritional components of B. napobrassica cv. Huaxi in fruit forest.
Table 2Growth dynamic of biomass of B. napobrassica cv. Huaxi during different growth stages during 2014-2015kg/plant
TreatmentItem
Investigation date
Sept. 20Oct. 5Oct. 20Nov. 5Nov. 20 Dec. 5Dec. 20Jan. 5
1Weight of aboveground part0.030.080.230.310.360.410.400.37
Weight of underground part-0.030.130.240.520.991.141.30
Weight of whole plant 0.030.100.360.560.881.391.541.67
2Weight of aboveground part0.030.090.260.350.400.450.450.42
Weight of underground part- 0.030.150.270.581.101.281.45
Weight of whole plant 0.030.120.400.620.981.551.721.87
3Weight of aboveground part0.030.100.290.390.450.510.500.47
Weight of underground part- 0.030.160.310.651.241.431.63
Weight of whole plant 0.030.130.450.701.101.741.932.09
Table 3Nutritional components of B. napobrassica cv. Huaxi under different planting patterns%
Treatment Moisture Crude protein Crude fat Crude fiber Nitrogenfree extract Crude ash CaP
189.341.4350.2480.9027.4980.4970.0360.044
288.411.5600.2700.9808.1500.5400.0390.048
387.831.6380.2841.0298.5580.5670.0410.050
Agricultural Biotechnology2019
Economic benefit of B. napobrassica cv. Huaxi planted under fruit forest by different methods
It could be seen from Table 4 that the economic benefit of treatments 1, 2 and 3 were 10 639.2, 14 116.8 and 16 674.0 Yuan/hm2, among which treatment 3 had the highest economic benefit, suggesting that treatment 3 could improve economic benefit for farmers. The results of multiple comparison showed that there were no significant differences between treatments 1 and 2 and between treatments 2 and 3 (P＞0.05), and there was a significant difference between treatments 3 and 1 (P＜0.05). Table 4Economic benefit of B. napobrassica cv. Huaxi under different planting patterns
Treatment Planting patternGrowth period∥dYield∥kg/hm2Output value∥Yuan/hm2Cost∥Yuan/hm2Net profit∥Yuan/hm2
1Hole sowing 122100 464.030 139.219 500.010 639.2
2drilling122112 056.033 616.819 500.014 116.8
3Seedling planting 122125 580.037 674.021 000.016 674.0
Variations of soil nutrients caused by planting B. napobrassica cv. Huaxi under fruit forest
It could be seen from Table 5 that after interplanting B. napobrassica cv. Huaxi under fruit forest, soil organic matter content and soil nutrient contents were improved to different degrees compared with the CK (soil under fruit forest, not planted with B. napobrassica cv. Huaxi). Among the various treatments, treatment 3 had the highest organic matter content, and its total N and total K contents were improved at the highest proportions. The three treatments had no significant differences in available nutrients and effective nutrients. It was indicated that interplanting B. napobrassica cv. Huaxi under fruit forest could improve soil physical and chemical properties and soil organic matter and nutrient contents to different degrees, thereby promoting growth of fruit forest as well as improving fruit quality.
Table 5Soil nutrients of planting B. napobrassica cv. Huaxi under fruit forest
Treatment pHOrganic matterg/kg
Total nutrient∥%
NP2O5K2O
Available nutrient∥mg/kg
NP2O5K2O
Effective nutrient∥mg/kg
CuZnFeMn
CK5.1013.800.1240.0250.672923770.550.5716.701.65
15.2017.010.1530.0210.71110511060.610.7349.315.30
25.0816.300.1480.0270.72511421080.590.7750.335.50
35.2217.500.1660.0260.75310821060.600.7151.205.01
Conclusions and Discussion
The results of this study showed that B. napobrassica cv. Huaxi could well adapt to soil and climatic conditions under fruit forest, and the crop and the fruit trees both could grow well. Among the three planting patterns (drilling, hole sowing and seedling transplanting) for B. napobrassica cv. Huaxi under fruit forest, seedling transplanting performed the best, achieved high fresh grass yield (125 580.0 kg/hm2) and better economic benefit (pure profit reaching 16 674.0 yuan/hm2), and could better improve soil physical and chemical properties and soil nutrient contents under fruit forest.
Compared with conventional clean tillage, interplanting forage under fruit trees could improve cropping index of unit area［5］, and could take full advantage of water and fertilizer under fruit forest to promote growth of fruit trees and improve yield and quality of fruit［6］. This method also could achieve the effects of improving soil fertility［7］, effectively improving microclimate in orchard［8］, reducing ground temperature and air temperature［9］, reducing environmental pollution, inhibiting road dust［10］, and significantly improving economic benefit, social benefit and ecological benefit. B. napobrassica cv. Huaxi has the advantages of good palatability, high yield, short production cycle and easy storage, and is favored by animals. It is a highquality green and juicy feed source for cattle, sheep and other animals. Interplanting B. napobrassica cv. Huaxi in orchard is simple in operation, easy to manage, harvest, store and use, and has high economic benefit. It can be further popularized and applied in production to realize the adjustment of agricultural industrial structure in povertystricken areas and increase farmers income.
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