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基于长期定位试验,对黄土丘陵区的晋西北河曲县砖窑沟试验区土壤氮素资源与分布,土壤氮素变化和农田氮素平衡进行了分析,并探讨了该区氮素管理策略和施肥方案。结果表明,试验区土壤全氮含量平均为0.4 g/kg,土壤碱解氮为16.76 mg/kg,氮素水平低,供氮能力差。土壤氮素含量呈现耕地>草地>林地的分布态势。经过连续13年的施肥处理,施有机肥和有机、无机肥配施0—20cm土层全氮含量显著提高了12.0%1~05.6%,20—40cm土层全氮含量变化没有显著差异;各施肥处理0—20cm土壤碱解氮均呈上升趋势,增加了32%2~99%,土壤有效氮的增加与连续施入有机肥的量有关。施肥处理的糜子农田的土壤氮素均呈现出盈余状况,马铃薯田则基本保持平衡。因此,在轮作周期中应根据前茬作物的需氮特性和收成情况确定当季作物的氮肥施用量。糜子和马铃薯的施肥应以氮肥和有机肥为主,氮磷比例分别为1∶0.50~.7和1∶0.7左右为宜。
Based on the long-term experiment, the soil nitrogen resources and distribution, soil nitrogen change and nitrogen balance in farmland were analyzed in the experimental area of brick kiln furrow in Hequ County, Northwest Shanxi Province in the loess hilly region. The nitrogen management strategies and fertilization schemes . The results showed that the total nitrogen content of the soil in the experimental area was 0.4 g / kg on average, the soil available nitrogen was 16.76 mg / kg, the nitrogen level was low and the nitrogen availability was poor. Soil nitrogen content showed the distribution of cultivated land> grassland> woodland. After 13 consecutive years of fertilization treatment, the total nitrogen content of 0-20cm soil with organic manure and organic and inorganic fertilizers increased significantly by 12.0% ~ 05.6%, while there was no significant difference in total nitrogen content of 20-40cm soil layers. Fertilization treatment 0-20cm soil alkaline hydrolysis nitrogen showed an upward trend, an increase of 32% 2 ~ 99%, soil available nitrogen increased with the continuous application of organic fertilizer. The soil nitrogen in the fertilized millet farmland showed a surplus, while the potato field remained basically balanced. Therefore, during the rotation cycle, the amount of nitrogen fertilizer applied to the crop should be determined according to the nitrogen requirement and crop yield of the previous crop. Millet and potato fertilization should be based on nitrogen and organic fertilizer, nitrogen and phosphorus were 1:0.50 ~ .7 and about 1:0.7 ratio is appropriate.