Study on soil water storage, crop yields and incomes under different soil tillage patterns with balance fertilization in the Loess Dryland region

【Objectives】 The semi-humid and prone-to-drought Loess Dryland is a typical rain fed agricultural region, where the mostly common crop system is once a year or once every two years. Reasonable rotation of tillage systems is important in maintaining the sustainable development of farmland ecosystem, the study on which will provide base for efficient crop production. 【Methods】 A long-term field experiment was conducted to investigate the effects of tillage patterns on yields, water use efficiency (WUE) and economic benefits of winter wheat and spring maize from 2007 to 2011 in Heyang County, Shaanxi Province. The tillage pattern treatments included: ploughingno-tillage ploughing no-tillage (RT1), subsoiling ploughing subsoiling ploughing (RT2), no-tillage subsoiling no-tillage subsoiling (RT3), no-tillage ploughing subsoiling no-tillage (RT4), and ploughing in 4 years (CK1), subsoiling in 4 years (CK2), 3 no-tillage in 4 years (CK3) for comparison propose. The soil water storage and water content in the 0-200 cm soil layer, the crop yields, water use efficiency and economic benefits were measured. 【Results】 1) During the fallow period, the highest soil water storage was in RT3, followed by RT2. The soil water storage in all the four treatments was significantly higher than in CK1, that in RT3 was also significantly higher than in CK3, and the difference between CK2 and RT3 was not significant. The highest soil water content was also found in RT3. 2) During winter wheat growth period, all soil water storage and soil water content in RT3 and CK2 were higher than in other treatments. 3) During spring maize growth period, both the soil water storages and contents in RT3 and CK3 were higher than in other treatments. 4) Both RT2 and CK2 showed the best effects in increasing crop grain yields, water use efficiencies and economic benefits. Compared with CK1, CK2 and CK3, the four years' average crop grain yields in RT2 increased by 10.2%, 3.6% and 17.1%, the net incomes by 23.6%, 6.8% and 28.3%, and WUE by 9.7% (P0.05), 4.3% and 18.6% (P0.05), respectively.【Conclusions】 Although the RT2 is not the best in saving soil water, it is best in improving WUE, crop yields and economic benefits. CK2 produces the highest water infiltration, water-holding capacity and soil-protecting capacity, although its crop yields is not as high as RT2. Considering the local conditions, RT2 and CK2 are recommended as suitable soil tillage patterns in the tested dry plateau area.