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以河北山前平原区秸秆还田条件下小麦-玉米轮作体系为研究对象,设置农民习惯、高产高效、再高产和再高产高效4个模式,通过定位试验探讨各栽培模式对3个轮作周期作物产量、土壤硝态氮累积量及氮平衡的影响.结果表明:小麦、玉米产量均以再高产模式最高,高产高效和再高产高效模式次之,均显著高于农民习惯模式;小麦季和玉米季氮肥利用效率(PFP)均以高产高效模式最高,显著高于其他模式;0~400 cm土体硝态氮累积量在768.4~1133.3 kg·hm~(-2)之间,其中80%~85%累积在根下90~400 cm土层;4种模式的土壤硝态氮均有明显向下淋移现象,120~150 cm和270~330 cm处均出现了累积峰,以270~330 cm土层硝态氮累积量最大;高产高效模式的土壤硝态氮含量整体水平均低于其他模式,浓度基本维持在30 mg·kg~(-1)以下,在一定程度上能有效缓解环境压力;冬小麦季0~90 cm土体氮素盈余量均小于夏玉米季,并以高产高效模式的氮素表观损失量最低,显著低于其他模式.综合考虑产量、氮肥利用效率、硝态氮累积和氮平衡,以高产高效模式表现最优,但还有一定的提升空间.
Taking the wheat-corn rotation system under the condition of straw returning to farmland in Hebei Piedmont Plain as the research object, four patterns of peasant habits, high yield and high efficiency, high yield and high yield and high efficiency were set up. The effects of different cultivation modes on three rotation crop Yield, soil nitrate accumulation and nitrogen balance.The results showed that the yield of wheat and maize were the highest in the pattern of high yield, the rate of high yield and high efficiency and the pattern of high yield and efficiency were the second, and the yield of wheat and maize The highest PUE was in high yield and high efficiency, significantly higher than those in other patterns. The accumulation of nitrate nitrogen in 0 ~ 400 cm soil layer was between 768.4 and 1133.3 kg · hm -2, of which 80% 85% accumulate in the soil layer of 90 ~ 400 cm under the root. The soil NO3 - N in all four kinds of soil showed a significant downward leaching phenomenon. The cumulative peak appeared at 120 ~ 150 cm and 270 ~ 330 cm, cm soil layer. The overall nitrate-N content of high-yield and high-efficiency soil was lower than the other modes, and the concentration of nitrate nitrogen remained below 30 mg · kg -1, which could effectively relieve the environment Pressure; winter wheat crop 0 ~ 90 cm soil nitrogen surplus were less than summer jade Compared with other models, the apparent N loss in the high-yield and high-efficiency model was the lowest, which was significantly lower than the other models.On the basis of yield, N use efficiency, nitrate accumulation and nitrogen balance, Improvement of space.