No-tillage and subsoiling increased maize yields and soil water storage under varied rainfall distribution: A 9-year site-specific study in a semi-arid environment

摘要

The application of conservation tillage with less soil disturbance appears to serve as an effective strategy to conserve water for crops. A site-specific field study was carried out in accordance with rainfall conditions to evaluate the influence of tillage methods on soil water regime, crop yield and water use efficiency for a semiarid region of the Loess Plateau in China. Three tillage methods including no-tillage, subsoiling, and plow tillage were tested from 2008 - 2016. Our results showed that the three tillage methods offer varying degrees of efficiency in conserving soil water and producing spring maize according to rainfall distributions. Compared to plow tillage methods, refraining from no-tillage increased soil water storage levels within the 0 - 200 cm layer by 7.1, 5.4, and 9.6% on an average in dry, normal and in wet years, respectively, subsoiling increased soil water storage levels by 5.1, 9.4, and 6.6% in dry, normal, and wet years, respectively. Improved soil water regimes secured by no-tillage and subsoiling respectively increased matter accumulation by 12.3% and 13.8% in dry years, by 12.3% and 18.6% in normal years, and by 13.9% and 9.2% in wet years. No-tillage and subsoiling respectively increased grain yields by 18.7% and 12.3% in dry years, by 2.9% and 8.8% in normal years, and by 9.1% and 7.9% in wet years relative to plow tillage. Consequently, water use efficiency levels achieved under the no-tillage and subsoiling methods were respectively increased on an average by 17.2% and 11.7% in dry years, by 3.1% and 8.5% in normal years, and by 9.3% and 6.0% in wet years. Hence, both the no-tillage and subsoiling methods could effectively improve soil water storage, thus significantly increasing yields and water use efficiency levels. With an increment of 10 mm of soil water storage, grain yield was increased up to 76.6 kg ha(-1). The proposed method could have important applications in semiarid areas.