论文部分内容阅读
【目的】探究不同施氮处理对水稻油菜轮作区土壤氮素养分及作物产量的影响,并重点分析不同处理在水稻油菜轮作间的差异及原因。【方法】2014—2015年在成都市典型水稻油菜轮作区进行连续两年小区定位试验,试验处理包括不施氮(CK)、单施尿素(UR)、40%控释氮肥+60%尿素(40%CRU)和单施控释氮肥(CRU)。研究不同处理对水稻油菜轮作条件下土壤无机氮、酶活性、作物产量及氮素利用率的影响。【结果】(1)相较UR处理,40%CRU处理能显著提高水稻生育中后期土壤无机氮含量;油菜蕾薹期到成熟期,土壤无机氮含量随控释氮肥添加量的增加而增大,40%CRU、CRU处理间无显著差异。(2)各施氮处理相比,在作物生育前期UR处理土壤脲酶和蛋白酶活性最高。随生育期推进,添加控释氮肥处理土壤酶活性均高于UR处理,但40%CRU、CRU处理间差异较小。两季作物相比,水稻季土壤脲酶和蛋白酶活性整体均呈升高-降低的趋势,孕穗期出现峰值;而油菜季土壤脲酶活性随生育期发展逐渐降低,添加控释氮肥处理蛋白酶活性先升高后降低。(3)水稻油菜产量均以40%CRU处理最大,两年水稻产量分别较UR处理增产597.04 kg·hm~(-2)(2014年)和582.61 kg·hm~(-2)(2015年),提高了7.50%—7.83%;油菜增产391.19 kg·hm~(-2)(2014年)和378.49 kg·hm~(-2)(2015年),提高了15.39%—16.70%。产量与构成因子的回归方程显示,水稻穗粒数和结实率与产量呈显著正相关,40%CRU处理穗粒数较UR处理提高15.17%(2014年)和17.72%(2015年),结实率提高4.49%(2014年)和4.44%(2015年)。油菜产量与每角粒数和总角果数相关性显著,40%CRU处理每角粒数最多,总角果数较UR处理两年分别增加8.98%(2014年)和13.80%(2015年)。(4)施氮显著提高水稻油菜成熟期地上部分氮积累量,且均以40%CRU处理最大。相较其余施氮处理,40%CRU处理的水稻成熟期氮积累量提高了6.21%—21.83%(2014年)、6.51%—20.74%(2015年),油菜成熟期氮积累量提高了8.42%—24.74%(2014年)、9.39%—22.77%(2015年)。施氮处理能有效提高水稻油菜作物的氮肥表观利用率、氮肥偏生产力和氮肥农学利用率,且均以40%CRU处理最优,CRU处理次之。【结论】添加控释氮肥的处理可有效改善水稻油菜生育中后期的土壤酶活性与氮素供应,显著增加水稻和油菜作物产量,提高氮素利用率。其中,控释掺混尿素处理土壤的氮素供应适宜,能有效促进作物对氮素的吸收利用,产量水平更大。
【Objective】 The objective of this study was to investigate the effects of different nitrogen treatments on soil nitrogen and crop yield in the rapeseed rape region and to analyze the differences and their causes of different treatments on the rapeseed. 【Method】 The plots of two plots were plotted for two years in a typical rice rapeseed area in 2014-2015. The treatments included CK, 40% CRU) and single-release controlled-release fertilizer (CRU). The effects of different treatments on soil inorganic nitrogen, enzyme activity, crop yield and nitrogen utilization rate under rapeseed rotation were studied. 【Result】 (1) Compared with UR treatment, 40% CRU treatment could significantly increase soil inorganic nitrogen content during late growth stage of rice. In rapeseed rape stage to maturity stage, soil inorganic nitrogen content increased with the increase of controlled release nitrogen fertilizer , 40% CRU, CRU no significant difference between the treatment. (2) Urease and protease activities were the highest in UR treatment before crop growth compared with those in other N treatments. As the growth period progressed, the enzyme activities of soil supplemented with controlled-release nitrogen fertilizer were higher than that of UR treatment, but there was no significant difference between 40% CRU and CRU treatments. Compared with the two seasons, the soil urease and protease activities showed a trend of increasing - decreasing at the booting stage and the peak at the booting stage. The urease activity of rapeseed soil decreased with the growth stage, and the activity of protease increased with the addition of the controlled release nitrogen fertilizer High after the reduction. (3) The yield of rice rapeseed was the highest at 40% CRU, and the yield of two years of rice increased 597.04 kg · hm -2 (2014) and 582.61 kg · hm -2 (2015) , Increased by 7.50% -7.83%; rape increased by 391.19 kg · hm -2 (2014) and 378.49 kg · hm -2 (2015), increased by 15.39% -16.70%. The regression equation between yield and compositional factors showed that there was a significant positive correlation between the number of grains per ear and the seed setting rate and grain yield. The number of grains per spike of 40% CRU was 15.17% (2014) and 17.72% (2015) Increase by 4.49% (2014) and 4.44% (2015). The yield of rapeseed was significantly correlated with the number of grains per ginkgo and the total number of pods. The number of grains per 40% CRU was the highest, and the number of total pods was 8.28% (2014) and 13.8% (2015) . (4) Nitrogen application significantly increased the above-ground nitrogen accumulation in rapeseeds at maturity, and the treatment with 40% CRU was the highest. Compared with the other treatments, the accumulation of nitrogen in matured stage of rice treated with 40% CRU increased by 6.21% -21.83% (2014), 6.11% -20.74% (2015), and the nitrogen accumulation in mature stage of rapeseed increased by 8.42% - 24.74% (2014), 9.39% - 22.77% (2015). N application could effectively improve the apparent nitrogen use efficiency, nitrogen partial productivity and nitrogen agronomic efficiency of rice rapeseed, and the best treatment was 40% CRU, followed by CRU. 【Conclusion】 The addition of controlled-release nitrogen fertilizer can effectively improve soil enzyme activities and nitrogen supply during middle and late growth stage of rice rapeseed, increase crop yield of rice and rapeseed significantly and increase nitrogen utilization efficiency. Among them, the controlled release of urea mixed with soil treatment of nitrogen supply is appropriate, can effectively promote crop nitrogen uptake and utilization, the output level is greater.