再生水灌溉时期和方式对作物生长及品质的影响

采用北京高碑店污水处理厂再生水(二沉池出水),以清水为对照,于2005—2006年进行了玉米和大豆种植盆栽试验,比较再生水不同灌溉方式(纯灌、与清水混灌和交替灌)和灌溉时期(全生育期、生育前期和后期)对作物生长、产量及品质影响。结果表明,再生水在玉米苗期灌溉对生长有一定抑制作用,但在拔节期后灌溉能明显促进玉米生长,玉米籽粒产量不降低或有所增加;再生水以纯灌和混灌方式在各个时期灌溉都能促进大豆整个生育期生长,明显促进籽粒产量提高。再生水灌溉对玉米和大豆籽粒粗蛋白、粗淀粉无显著影响,但粗灰分效应有别。再生水灌溉降低玉米籽粒铁含量,重金属铅和镉在玉米和大豆不同器官内含量不同,其分布规律是:根>茎、叶>>籽粒,再生水灌溉的玉米和大豆籽粒中铅和镉含量均满足国家粮食安全标准,但再生水灌溉有增加大豆籽粒中镉含量的趋势。这些结果对评价再生水灌溉对作物生产影响及应用有重要参考意义。

Effect of Irrigation Time and Mode with Reclaimed Water on Growth and Quality of Crops

Using pot experiments, the effects of irrigation time (such as whole growth period, ante-development period and step-development period) and irrigation modes(such as all irrigation with reclaimed water, mixed irrigation with reclaimed water and tap water, rotating irrigation with reclaimed water and tap water) on growth, yield and quality of maize (Zea mays L.) and soybean (Phaseolus vulgaris L.) were compared. The reclaimed water was from the di-sinking pool in Beijing Gaobeidian sewage treatment plant, and tap water was used in the control treatment in 2005-2006. The results showed that growth of maize at seedling stage was inhibited to some degree with reclaimed water irrigation, and after jointing stage with reclaimed water irrigation, the growth showed a positive effect, and the yield of maize did not decrease or increased a little. To the soybean, reclaimed irrigation or mixed with tap water irrigation at any growth stage all enhanced the growth, and increased the grain yield markedly. The general quality of crude protein and crude starch in the grain showed no significant differences between the control and the treatments irrigated with reclaimed water, only crude ash was different in maize and soybean. The residual quantity of heavy metals such as lead and cadmium varied greatly with different parts of the crop, highest in roots, middle in shoots and leaves and lowest in grain. However, the heavy metal content in the grain of maize and soybean met the requirement of National Food Sanitation Stands, but the contents of Cd in the grains of soybean tended to increase under irrigation with reclaimed water. These would provide an important reference for estimating the influence of reclaimed water irrigation on crop quality and rationally utilizing of reclaimed water in China.