水肥耦合对大豆棵间土壤蒸发及水分利用效率的影响

摘要

为了确定沈阳地区潮棕壤土条件下大豆田间管理的最优水肥用量，采用分根交替灌溉技术，通过不同的水肥配合比，利用微型蒸发器，研究水肥耦合对大豆整个生育期的土壤棵间蒸发及水分利用效率的影响。结果表明：在大豆整个生育期内，棵间蒸发占总耗水量的35.99%～38.21%，不同处理间棵间土壤蒸发量为：W2N0跃W1N0跃W2N1跃W2N2跃W1N1，说明适量追施氮肥能够有效地抑制棵间土壤蒸发；不同水肥处理对大豆生育期棵间蒸发有一定的影响，最大相差达11.58mm；而对叶面蒸腾的影响较大，最大相差达18.17mm；不同处理下的蒸发强度与叶面积指数呈显著负相关，同时与表层土壤含水率呈显著正相关，二者决定系数均在0.77以上。处理W1N1减少了棵间蒸发，提高了作物水分利用效率。%To predict the optimal amount of water and fertilizer in brown earth in Shenyang region and guide the soybean field management, the alternate partial root irrigation techniques with the ratio of different water and fertilizer and the micro-lysimeters were employed to determine the soil evaporation and water use efficiency of soybean at its whole growth stages under water and fertilizer coupling. Soil evaporation in soybean field accounted for 35.99%-38.21% of water consumption in the whole growth stages. Soil evaporation decreased in the order of W2N0>W1N0>W2N1>W2N2>W1N1. The effects of evaporation were small under the different water and fertilizer treatments on soybean growth, the maximum difference was only11.80 mm in leaf transpiration,the biggest difference was 18.17mm in evaporation. At the same time ,with the surface soil moisture content was a significant positive correlation, both the correlation coefficient of determination were above 0.77. W1N1 trectment is the best mode of water and fertilizer to decrease soil evaporation and to raise water use efficiency.