【摘要】 为解决由于长期不合理耕作及有机物料利用率低而导致土壤养分贫瘠和土壤物理性状恶化情况,本试验针对黑土宜板结和肥力保持等问题设置了不同技术措施,研究在玉米生育时期不同有机物料还田模式对土壤结构特性及玉米光合速率的影响。结果表明:收获后浅翻深松+秸秆还田和有机肥处理较常规处理,土壤容重下降了0.13 g·cm-3和0.09 g·cm-3,浅翻深松+秸秆还田、有机肥、翻压绿肥和生物肥均能降低土壤紧实度,改善土壤三相比,增加土壤通气透水性,使得土壤物理结构得到改善。有机肥、秸秆还田和生物肥处理提高玉米喇叭口期光合速率,较常规处理提高2.1~7.6μmol·m-2·s-1;秸秆还田和生物肥较常规施肥处理,蒸腾速率下降57%和56%;在玉米喇叭口期各处理气孔导度均小于对照,灌浆期秸秆还田处理较常规处理气孔导度增加,导致叶片胞间CO2浓度下降,说明气孔阻力的降低导致叶片胞间CO2浓度降低。有机物料还田后可以降低土壤容重、紧实度,土壤三项比达到合理范围,并且可以提高作物的光合速率,降低蒸腾速率,尤其是秸秆还田和有机肥处理好于其他处理。保护性耕作和有机物料还田对于提高土壤肥力、改善土壤物理特性,提高作物光合速率,增加作物产量均起到积极促进作用。更多还原

【Abstract】 The effect of different organic material turnover on soil structure and maize photosynthetic rate was researched in this paper. The results showed that comparing the control treatment, the soil bulk density of two treatments of shallow reversing and chiseling plow with straw returning and organic fertilizer were decreased by 0.13 g·cm-3and 0.09 g·cm-3, respectively. The application of shallow reversing and chiseling plow with straw turnover,organic fertilizer, green organic fertilizer and bio-fertilizer could reduce soil hardness, change the soil three phase state, improve the soil physics structure. Organic fertilizer and green organic fertilizer and bio-fertilizer increased the maize photosynthetic rate at trumpet period by 2.1~7.6 μmol·m-2·s-1. The transpiration rate of straw turnover and bio-fertilizer treatments was decreased by57% and 56% separately. Conductances of all treatments were lower than that of the control treatment at trumpet period. Meanwhile stomatal conductance was increased at filling stage which may lead to the decreasing CO2concentration with the reason that reducing of stomatal booster caused the lower CO2concentration. Returning of organic materials could reduce soil bulk density and com paction, make the soil three phase state having a reasonable range, improve crop photosynthetic rate, decrease the transpiration rate, especially the treatments of straw returning and organic fertilize. In short, protection tillage and organic materials returning to field play a positive role for improving soil fertility, soil physical characteristics, crop photosynthetic rate and crop yields.更多还原