Soil water conservation effect, yield and income increments of conservation tillage measures on dryland wheat field

In the study the experiment about effects of different conservation tillage measures on soil water retention in summer fallow and its impact on winter wheat yields and economic returns were conducted on continuous cropping wheat field of Weibei Highland. A field experiment was carried out in 2007-2009 on dryland wheat fields of Weibei Highland. The study included the effects of three tillage treatments (no-tillage, sub-soiling and deep plowing) on soil water conservation in summer fallow, as well as its effects on soil water dynamic during wheat growth period, wheat yield and economic returns under three tillage treatments combined with three fertilizer treatments (balanced fertilization, traditional fertilization and low fertilization). The results showed that no-tillage and sub-soiling had better soil moisture conservation effects than deep plowing in summer fallow. During summer fallow of three trial , average soil water content in 0-300 cm soil layer of no-tillage and sub-soiling treatments were 0.6 and 0.5 percentile higher than that of deep plowing, and average water storage increased 24.2 mm and 21.5mm, respectively. During winter wheat growth period, average water storage in 0-200 cm soil layer of no-tillage and sub-soiling treatments increased 17.7 mm and 14.4 mm, respectively, compared to deep plowing treatment in two wheat growth seasons. Sub-soiling combined with balanced fertilization was the highest yield treatment among all treatments. Its average yield in two wheat production seasons was 5 033.1 kg/hm2, and it was 5.5% and 6.3% higher than deep plowing and no-tillage combined with balanced fertilization treatments, respectively. No-tillage combined with balanced fertilization was the highest economic benefit treatment among all treatments. Its average net return in two wheat production seasons was 5 553.7 yuan/hm2, and it was 3.3% and 9.2% higher than sub-soiling and plowing combined with balanced fertilization, respectively. This study comprehensively concluded that considering soil water retention effect, wheat yield increment and economic benefit, sub-soiling combined with balanced fertilization treatments were the preferable conservation tillage and fertilization combination treatments on continuous cropping of dryland wheat field in Weibei Highland