液体地膜覆盖对棉花生理特性的影响

研究结果表明，液体地膜覆盖棉花根系伤流中游离氨基酸总量和无机磷含量明显增加，根系活力增强；叶片光化学特性得以改善，光合效率提高；发育的棉铃中转化酶活性增强，加速了光合产物向棉铃中运输的速度。

Effects of Liquid Film Mulching on the Physiological Characteristics of Cotton

Liquid film,also called multi-functional and degradable liquid film,is a kind of new macromolecule organic compounds that form a very thin film when mixed with water and then sprayed on the soil surface.Some workers have reported the good effects of liquid film mulching on cotton growth.In this study,effects of liquid film mulching on the physiological characteristics of cotton were studied with two objectives:(1) to investigate effects of liquid film mulching on the physiological characteristics of cotton;and(2) to provide theoretical basis for application of liquid film in cotton production practice.The experiment was conducted from 2002 to 2004 on a sandy loam nursery at Henan Agricultural University Experiment Station.The liquid film used was prepared by Henan Agricultural University.The treatments were different application rates: 75.0,112.5,150.0,187.5 kg/ha,and control(no mulching).Liquid film was sprayed on soil surface at a dilute rate of 20.The final amount of water applied to each plot was the same.Cover percentage was 60%.A random block design was employed with three replications.Fluorescence parameters of chlorophyll in cotton leaves were measured by a portable fluorometer(FMS-2,USA) at full budding,full flowering,and boll opening stage.Bleeding root sap was collected by a volumetric method,and contents of amino acids and inorganic P were determined by acidic ninhydrin reaction method and silicomolybdic blue method at first budding,full budding,first flowering,full flowering,and boll opening stage.Activity of sucrose invertase in cotton bolls was determined by DNS method at 10,15,20,25,and 30 d after flowering.The experimental results showed that root bleeding sap in cotton plants in which the contents of free amino acid and inorganic phosphorus were raised,which indicated that the root activity was enhanced effectively;leaf photochemical characteristics were improved and activity of sucrose invertase enhanced in developing bolls,which improved the photosynthetic efficiency and promoted the accumulation of dry matter in cotton fruits.In addition,liquid-film also had the following advantages: easy to use,low cost,biologically degradable,and no environmental pollution.Based upon above analysis,the author concludes that application of liquid film is a feasible technique in cotton production practice.