旱作麦田保护性耕作蓄水保墒和增产增收效应

为了揭示渭北旱塬连作麦田不同保护性耕作措施下土壤蓄水保墒效果和冬小麦增产增收效应。于2007－2009年通过田间试验研究了渭北旱塬夏闲期免耕、深松和翻耕等3种耕作方式对麦田夏闲期蓄水保墒效果，以及3种耕作处理与平衡施肥、常规施肥和低肥等3种施肥处理组合对冬小麦生育期土壤水分动态、产量和经济效益的影响。免耕和深松较翻耕保墒作用好，夏闲期免耕、深松较翻耕0～300 cm土层3 a平均土壤含水率分别增加了0.6和0.5个百分点，平均贮水量分别增加了24.2和21.5 mm；生育期内平衡施肥免耕、深松较翻耕处理0～200 cm土层2 a平均土壤贮水量分别增加了17.7和14.4 mm；以平衡施肥深松处理产量最高，2 a平均产量高达5033.1 kg/hm2，较平衡施肥翻耕和平衡施肥免耕分别增产5.5%和6.3%；以平衡施肥免耕经济效益最高，2 a平均纯收益高达5 553.7元/hm2，较平衡施肥深松和平衡施肥翻耕分别增收3.3%和9.2%。综合考虑各处理土壤蓄水保墒效果和小麦增产增收效应，平衡施肥深松处理是渭北旱塬连作麦田较佳的耕作和施肥处理组合。

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