耕作模式与氮肥运筹对土壤主要理化性状及作物产量的影响

摘要

The effects of various tillage practices(including deep tillage and rotary tillage in wheat field,no tillage in maize field)and different nitrogen fertilization(including the rate and method of nitrogen application)on annual varia-tion of soil physical characteristics and crop yield were investigated,by field experiments including fluvo -aquic soil and lime concretion black soil under the condition of winter wheat -summer maize rotation cropping system at the same time. Aikang 58(wheat)and Zhengdan 958(maize)were used as the test materials.The results showed that deep tillage de-creased the soil bulk density whereas increased the soil porosity and field moisture in 20~40 cm soil layer significantly, and the annual crop yield were increased by 4.30% and 2.63% in both experiments of deep tillage compare to the rotary tillage.Soil total nitrogen and alkali -hydrolyzable nitrogen were with the increase in nitrogen application rate.Soil total nitrogen and alkali-hydrolyzable N increased with the increase in base fertilizer application,and they increased with the increase in nitrogen topdressing rate.Considering the economic benefit,we suggest that deep tillage in winter wheat field and no tillage in summer maize field is the most appropriate tillage methods in both experiments.Nitrogen application rate of 300 kg/hm-2and the ratio of base to jointing topdressing as 1:1 in winter wheat and Nitrogen application rate of 240 kg·hm-2and the ratio of base to jointing topdressing to bell stage as 2:1:1 in summer maize was the optimal nitrogen ap-plication model in fluvo -aquic soil.And nitrogen application rate of 240 kg·hm-2as the base fertilizer in winter wheat and nitrogen application rate of 180 kg·hm-2and the ratio of base to jointing topdressing as 3:1 in summer maize was the optimal nitrogen fertilization model in lime concretion black soil.%在冬小麦-夏玉米轮作条件下,以小麦品种矮抗58和玉米品种郑单958为材料,研究了不同耕作方式(小麦季深耕、玉米季免耕;小麦季旋耕、玉米季免耕)及不同氮肥总量(540,420,300 kg·hm-2)和不同氮肥运筹方式(不同追肥比例及追肥时期)对豫东潮土和豫南砂姜黑土物理性状及氮含量的周年变化以及作物产量的影响.结果表明:深耕能显著降低潮土和砂姜黑土20~40 cm土层土壤容重,显著提高两类土壤20~40 cm土层土壤总孔隙度以及田间持水量,且深耕处理下两类土壤周年作物产量分别比旋耕处理增加4.30% 和2.63%;土壤全氮以及碱解氮含量均随着氮肥施用总量的增加而升高,在氮肥施用量相同条件下,追施氮肥前土壤全氮和碱解氮含量随着底施氮量的增加而升高,追施氮肥后随着追氮量的增加而增加.研究认为,本试验条件下,考虑到经济效益,建议采用小麦季隔年深耕而玉米季免耕直播的耕作方式,在潮土区的B1C3(小麦季300 kg·hm-2纯氮,按照底肥与拔节期追肥之比为1:1施入,玉米季240 kg·hm-2纯氮,按底肥与拔节期追肥大喇叭口期追肥之比为2:1:1施入)施肥模式,和砂浆黑土地区的B2C1(小麦季240 kg·hm-2全底施,玉米季180 kg·hm-2纯氮,底肥与拔节期追肥之比3:1施入)施肥模式为两地最优的氮肥施用模式.