Effects Of Tillage Practices And Nitrogen Fertilizer Application Regimes On Main Physical & Chemical Properties Of Soil And Crop Yield

In winter wheat and summer maize field,taking Aikang 58 and Zhengdan 958 as the test materials,dynamics of soil physical and chemical properties and crop yield were studied under two tillage patterns(including deep tillage and rotary tillage in wheat field,no tillage in maize field)and nitrogen application regimes both in fluvo-aquic soil and lime concretion black soil.The main results were as follows:1.The results showed that the effects of different tillage on the soil bulk density and the soil porosity in 0-20 cm soil layers were not significant both in fluvo-aquic soil and lime concretion black soil.Deep tillage can significantly depressed the soil bulk density and increased the soil porosity and the field moisture capacity in 20-40 cm soil layers.In 20-40 cm soil layers,compared with rotary tillage,the soil bulk density performance for deep tillage was lower than that of 2.70% and 1.7% in fluvo-aquic soil and lime concretion black soil.The soil porosity and the field moisture performance for deep tillage was higher than that of 3.30% and 7.4% in fluvo-aquic soil,and higher than that of 2.1% and 6.0% in lime concretion black soil.The soil physical properties did not respond to the nitrogen fertilizer application regimes.2.Effects of tillage practices and nitrogen fertilizer application regimes on soil total nitrogen content and alkali-hydrolyzable N content.Deep tillage was beneficial to the improvement of soil total nitrogen content and alkali-hydrolyzable N content in 20-40 cm soil layer.But in 0-20 cm soil layer,the soil total nitrogen content and alkali-hydrolyzable N content of deep tillage were lower than rotary tillage.In 0-20 cm soil layer,compared with rotary tillage,the content of total nitrogen performance for deep tillage was lower than that of 5.3% and 6.4% in fluvo-aquic soil and lime concretion black soil,while the content of alkali-hydrolyzable N performance for deep tillage was lower than that of 3.1% and 6.1% in fluvo-aquic soil and lime concretion black soil.In 20-40 cm soil layer,compared with rotary tillage,the content of total nitrogen performance for deep tillage was higher than that of 7.6% and 12.7% in fluvo-aquic soil and lime concretion black soil,while the content of alkali-hydrolyzable N performance for deep tillage was higher than that of 1.8% and 17.7% in fluvo-aquic soil and lime concretion black soil.With the increasing of the nitrogen application rate,the soil total nitrogen content and alkali-hydrolyzable N content increased.Under the same nitrogen application rate,before the topdressing,with the increasing of the base nitrogen,the soil total nitrogen content and alkali-hydrolyzable N content increased.After the topdressing,the soil total nitrogen content and alkali-hydrolyzable N content increased with the increasing of the topdressing.3.Effects of tillage practices and nitrogen fertilizer application regimes on crop yield and the grain protein content.Compared with rotary tillage,deep tillage was beneficial to the improvement of the annual crop yield.The yield of winter wheat and summer maize and annual crop performance for deep tillage was higher than that of 3.1%,5.2% and 4.3% in fluvo-aquic soil,1.7%,3.7% and 2.6% in lime concretion black soil.In fluvo-aquic soil,the crop yield of B1 was higher than B2 and B3 significantly,and C3 could significantly increased the crop yield.In lime concretion black soil,the crop yield of B2 was the highest,and the method of nitrogen application had no significant impact on crop yield.Different tillage pratiices had no significant impact on grain protein content of wheat in two soil types.While B1 was obviously higher than B2 and B3 in lime concretion black soil,C3 was the best in two soil types.4.As far as annual dynamics of soil physical and chemical properties and annual crop yield were concerned,we recommend that deep tillage every other year in winter wheat field and no tillage in summer maize field is the most appropriate tillage patterns in high-yielding and cost saving production in fluvo-aquic soil and lime concretion black soil.N rate of 300 kg/ha and ratio of base to jointing topdressing 5: 5 in winter wheat and N rate of 240 kg/ha and ratio of base to jointing topdressing to bell stage 5 : 2.5 : 2.5 in summer maize was the optimal nitrogen application model in fluvo-aquic soil.And N rate of 240 kg/ha and ratio of base to jointing topdressing 10 : 0 in winter wheat and N rate of 180 kg/ha and ratio of base to jointing topdressing 7.5 : 2.5 in summer maize was the optimal nitrogen application model in lime concretion black soil.