覆膜栽培对盐碱地水稻生长的影响及节水潜力初探

摘要

A field experiment was conducted in order to investigate and understand the effects of mulching on rice growth and water saving potential in saline-sodic soil. The results showed that rice heading was promoted by mulching cultivation (MC) ,and rice grains per ear, grain weight per one thousands, seed rate and harvest index were increased in MC treatment than those in CK. Because a wide and narrow row planting patterns was applied, plant density increased, as a result, rice tillering was inhibited, and rice yield was slightly lower than that in conventional cultivation (CK) in saline-sodic soil. The growth characteristics of rice was not significant different between MC treatment and CK treatment, but EC and pH of soil were significantly reduced in MC compared with those in CK. For example,EC and pH of soil (0 - 10 cm) was decreased by 0. 35 -0.48 dS/m and 0. 3 units in MC treatment than those in CK in rice tillering stage,respectively. Compared with conventional cultivation (CK) irrigation water was reduced by 17% in MC treatment, and water productivity was increased. The loss of soil available nutrients was reduced in MC treatment than that in CK, and the soil fertility was increased. Therefore, we need to develop practices that can maximum the role of water saving and salt control with mulching,while considering planting density and nutrient supply for higher grain yield of rice in saline-sodic soil.%采用田间试验方法,研究了覆膜栽培对盐碱地水稻生长的影响,并对盐碱地水稻覆膜栽培的节水潜力进行了初步探讨.结果表明,覆膜栽培可促进水稻抽穗,提高了盐碱地水稻穗粒数、千粒质量、结实率和收获指数,但由于覆膜采用了宽窄行种植模式,改变了插秧密度,导致膜上密度增大,抑制了水稻分蘖,造成水稻产量略低于常规栽培.与常规栽培相比,覆膜栽培降低了盐碱地稻田表层土壤pH值和盐分含量,有利于水稻植株前期的生长,以分蘖期为例,覆膜栽培处理表层(0～10 cm)土壤pH值较常规栽培处理下降了0.3个单位,电导率(EC)下降了0.35～0.48dS/m.盐碱地水稻覆膜栽培可较常规栽培节水17％,提高了水分生产力,并且有利于减少土壤速效养分的流失,具有培肥土壤的作用,但也造成追肥困难,容易出现后期脱氮现象.因此,盐碱地水稻种植既要充分发挥覆膜栽培节水、抑盐的作用,也要全面考虑覆膜后合理移栽密度和肥料的有效供应,才能真正实现水稻高产.