覆膜后土壤水分对水稻生物学特性和产量的影响

采用控制土壤水分盆栽试验，来研究覆膜后不同土壤水分对水稻生物学特性及产量的影响。结果表明，随着土壤水分含量降低，分蘖渐变晚、慢、少，各生育期株高、主要功能叶叶面积降低，叶绿素含量升高，成穗率和收获指数先升高后降低，生物量和产量逐渐降低。与常规水作稻相比，土壤水分较高的覆膜处理（下限为田间持水量±5%）分蘖早、快、多；各生育期株高、主要功能叶叶面积、有效穗数、结实率有所增加，叶绿素含量无差异，生物量和产量有所提高。覆膜旱作分蘖初期应保持富足土壤水分（下限为饱和含水量），促进水稻茎蘖数；分蘖后期应适当控水［（田间持水量～80％田间持水量）±5%］，有效控制无效分蘖，提高成穗率；孕穗期应保持充足土壤水分（下限为饱和含水量），利于提高穗粒数；抽穗开花期和灌浆期应保持湿润（饱和含水量左右），可促进千粒重提高，利于覆膜旱作水稻高产。

Effects of soil moisture under plastic film mulching on the biological and yield characteristics of rice (Oryza sativa L.)

Pot culture was adopted in this experiment to study the effects of different levels of soil moisture on the growth and yield of rice under plastic film mulching condition. The results showed that the tiller produced later,and more slowly with less number,the plant height and leaf area of main functional leaves decreased,chlorophyll content of main functional leaves increased, effective panicle ratio and harvest index were first enhanced and then depressed, the biological mass and yield of rice reduced gradually along with the decrease of soil moisture under plastic film mulching condition. Comparing with the treatment of traditional flooding (TF) ,the treatments of higher soil moisture (above field water capacity (FWC)±5%) under film mulching condition enhanced tillering,plant height, main functional leaves area,effective panicles,ripening grains rate,biological mass and yield of rice. At the beginning stage of tillering,it was necessary to keep enough soil moisture (above saturated water content SWC) for the rice filled under plastic film mulching dryland cultivation to enhance tillering;however,it was important to control the proper level of soil moisture (FWC-80% FWC)±5%] to restrain invalid tillering at the later stage of tillering. At the booting stage,the soil moisture should be kept above SWC to increase the grains of panicle,while at blooming and filling stage,the soil moisture should be kept up to SWC to promote 1000-grain weight and to facilitate high yield of rice.