耕作方式对豫南雨养区土壤微环境及冬小麦产量的影响

针对豫南雨养农业区降水基本满足作物生长需求但年内和年际间分配不均、土壤耕性差的生态实际,为解决小麦播种期和冬春干旱以及改善耕层水、肥、气、热等因子提供理论依据。于2007—2015年,在豫南雨养农业区进行了连续9a的大田定位试验,研究了不同耕作模式对小麦生长季土壤水分、容重、温度及冬小麦产量的影响。试验共设置6个处理:T1(传统翻耕)、T2(不覆盖/不深松+覆盖/免耕)、T3(覆盖/不深松+不覆盖/免耕)、T4(不覆盖/深松+不覆盖/免耕)、T5(覆盖/深松+覆盖/免耕)以及T6(不覆盖/不深松+还田/旋耕)。结果表明,(覆盖/深松+覆盖/免耕)T5可以有效提高小麦播种期0~40cm土层的含水量,为麦播提供较好的水分基础,不同耕作方式处理对冬小麦越冬期和返青期土壤日平均温度影响较小,不足以对冬小麦发育进程产生影响。(覆盖/深松+覆盖/免耕)T5能够有效降低耕层0~20cm和0~40cm的土壤容重。覆盖/深松+覆盖/免耕处理的前3a,冬小麦产量较对照有所降低,从第4年开始较对照增产,2011—2015年增产幅度分别为2.02%、2.83%、10.93%、5.88%、1.97%。以上结果表明,通过T5(覆盖/深松+覆盖/免耕)的简耕覆盖技术可以有效利用降水资源、培肥地力,提高产量,具有节本增效的作用。

Effects of tillage regimes on soil micro-environments and yield of winter wheat in rainfed areas in southern Henan province, China

There was the ecological reality that the precipitation amount basically meet the crop needs but the inter- and intra-annual precipitation was unevenly distributed in rainfed areas in south of Henan province, and poor tillage also limited agriculture development. The paper provided a theoretical basis in order to solve the problems of sowing drought, the winter and spring drought, and improve topsoil water, fertilizer, gas, heat and other factors. The effects of different tillage regimes on the soil temperature,water content, bulk density and yield of winter wheat in the rain-fed farming region in southern Henan of China was studied. The experiment was conducted from 2007 to 2015, with six treatments, i.e., T1(traditional tillage and cultivation), T2(non-straw-mulching for corn + straw mulching and non-tillage for wheat), T3(straw mulching for corn + non-tillage for wheat), T4(pre-sowing deep plough for corn + non-tillage for wheat), T5(straw mulching and pre-sowing subsoiling for corn + straw mulching and non-tillage for wheat) and T6(straw mulching and rotary tillage). The results showed that, straw mulching and subsoiling effectively improved soil water content, and reserved higher soil water content in 0-40 cm soil layer at the seeding stage. There were less difference of the average temperature among different treatments during the wintering period and turning green stage. Meanwhile, straw mulching and pre-sowing subsoiling for corn + straw mulching and non-tillage for wheat non-tillage regimes effectively reduced 0-40 cm soil bulk density. In the first three years, the yearly average yield of straw mulching (T5) was lower than T1(CK), while from the fifth fourth year, the yield of (straw mulching)T5 treatment started to increase by 2.02%、2.83%、10.93%、5.88%、1.97% from 2011 to 2015. These results suggests that (straw mulching)T5 regime can effectively use precipitation resources, and also increase soil fertility and yield of winter wheat in rainfed areas in southern Henan province.