| To investigate the effect of different conservation tillage measures combined with different fertilizer treatments on soil water conservation, grain yield and income increments on spring maize field of Weibei Highland, a two-year-field experiments was conducted to measure soil moisture of returning straw to field combined with no-tillage, sub-soiling and deep-plowing treatments during winter fallow and maize growth period in 2007-2009, maize agronomic traits, physicochemical characteristics of maize field of harvesting time were observed as well, and its effects on maize yield and economic benefits, the difference of maize agronomic trait and the change of physicochemical characteristics of maize field combined with balance fertilization, conventional fertilization and no or lower fertilizer treatments were analysed. The main research results are as follows:1. Effects of different conservation tillage treatments on soil physical properties and soil water conservation of maize fieldUnder different fertilization practices, soil bulk density of no-tillage was the highest one, sub-soiling was in the second place and deep plowing treatment was the lowest one, no-tillage increased the quantity of soil aggregate with diameter higher than 0.25mm in 0~10cm surface soil layer and contributed to the form of soil waterstable aggregate; the saturated soil water content and maximum field capacity of no-tillage and sub-soiling treatments were higher than deep-plowing in 0~20cm soil layer, the soil respiration of sub-soiling was higher than no-tillage and deep-plowing treatments.In winter fallow of maize field, no-tillage and sub-soiling treatments were beneficial to increase the soil water storage in 0~200cm soil layer, the tillage of "no-tillage-no-tillage" and "sub-soiling-sub-soiling" 's soil water storage increased 49.4 mm and 42.5 mm in average than "sub-soiling-deep-plowing" rotation tillage treatment in 0~200cm soil layer respectively; during the growing season of maize, the soil water storage of no-tillage and sub-soiling increased 36.3mm and 37.3mm in average than deep-plowing treatment in 0~200cm soil layer respectively, while the soil water storage capacity of "no-tillage-sub-soiling" and "sub-soiling-sub-soiling" were better than "deep plowing-deep-plowing" rotation tillage treatment in 0~200cm soil layer, in detail, the soil water storage in 0~200cm soil layer of "sub-soiling-sub-soiling" and "no-tillage-sub-soiling" were 38.9mm and 35.9mm higher than "deep-plowing-deep-plowing" rotation tillage treatment.2. Effects of different conservation tillage treatments on soil fertility of maize fieldNo-tillage and sub-soiling treatments improved the accumulation of soil organic matter in 0~20cm layer in winter fallow effectively, and no-tillage was good for the increase of the soil total nitrogen content, alkali-hydro nitrogen content and total K content of 0~20cm soil layer, sub-soiling treatment improved total nitrogen content of 20-60cm soil layer. In the balanced fertilization and conventional fertilization condition, no-tillage was in farvour of the increase of the soil organic matter content, total nitrogen content, total K content and available K content of 0~20cm soil layer, while sub-soiling was good for the increase of soil organic matter content and total nitrogen content; in no or low fertilizer condition, sub-soiling availed to the decompose of available P and alkali-hydro nitrogen of 0~20cm soil layer, no-tillage made against the release of total P of 0~20cm soil layer.3. Effects of different conservation tillage treatments on agronomic trait and maize yield Under three fertilization treatments, the weight of stem leaf, grain weight, corncob weight and root weight of spring maize of sub-soiling treatment were exceed than no-tillage and sub-soiling, deep-plowing treatment's maize stem lenght was the highest, no-tillage was the lowest; the growth of maize under balanced fertilization was superior to conventional fertilization and no or low fertilizer treatments. During the grain-filing stage, the transpiration rate, photosynthetic rate and stomatal conductance of spring maize of sub-soiling were superior than no-tillage and deep-plowing treatments.Among different fertilities practices, the yield and water use efficiency of spring maize with balanced fertilization treatment was the best and conventional fertilization was in second place and no or low fertilizer treatment was the worst. Among 9 combinations of different fertilizer and farming practices of continous tillage treatments, the spring maize yield and water use efficiency of balanced fertilization with sub-soiling treatment was highest, in detail, the yield and water use efficiency was improved 9.4%, 9.9% and 13.7%, 9.4% than balanced fertilization with no-tillage and balanced fertilization with deep-plowing treatment respectively; the spring maize yield of conventional fertilization with sub-soiling and no-tillage treatments were improved 15.7% and 3.7% than conventional fertilization with deep-plowing treatment respectively; in no or low fertilizer treatment, the yield of sub-soiling treatment was highest and no-tillage treatment was lowest. Under rotation tillage treatments, the spring maize yield and water use efficiency of balanced fertilization with "sub-soiling-sub-soiling" treatment was highest and the yield and water use efficiency were improved 2.7%, 12.9% and 5.1%, 23.9% than balanced fertilization with "no-tillage-sub-soiling" and balanced fertilization with "sub-soiling-deep-plowing" treatments respectively among 7 different kinds combination of fertilization and tillage treatments; in conventional fertilization treatment, the maize yield of "sub-soiling-sub-soiling" and "no-tillage-no-tillage" treatments were improved 21.9% and 10.1% than "deep-plowing-no-tillage" treatment respectively; under no-fertilizer to low-fertilizer treatment, the yield of "sub-soiling-sub-soiling" treatment was the highest and "deep-plowing-no-tillage" treatment was the lowest.4. Effects of different conservation tillage treatments on economic benefits of maize fieldUnder continous tillage treatments, the net return of balanced fertilization with sub-soiling was highest, balanced fertilization with no-tillage was in the second place, balanced fertilization with deep-plowing was lowest; Under rotation tillage treatments, the net return of balanced fertilization with "sub-soiling-sub-soiling" was higher than balanced fertilization with "no-tillage-sub-soiling" and balanced fertilization with "sub-soiling-deep-flowing" was in the third place.Under different fertilization treatments, the economic benefits of sub-soiling treatment was the best while deep-plowing treatment was the worst, the effects of maize yield and income increments of sub-soiling were superior to no-tillage and deep-plowing treatments. |
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