生物降解地膜周年降解特性对北方灌区玉米增产机理研究

Abstract

生物降解地膜是解决地膜残留污染问题的重要途径，对农业发展潜力巨大，但不同生物降解地膜对不同生态区域玉米生长的适配性各异，影响其推广应用。本文通过大田试验，从地膜田间降解特性、土壤保温性、作物生长发育、产量及其构成因子、残留地膜覆盖率等方面对9种可降解生物地膜与普通PE (CK1)地膜和露地栽培(CK2)进行了对比研究。结果表明：试验筛选出GS05、GS09、GS10和GS03四种生物可降解地膜，玉米生长前期降解缓慢，中期和后期降解较快，与玉米生长发育适配性较好；10 cm处土层地温在玉米全生育期、出苗至拔节期、抽雄至灌浆期分别比CK1降低0.1℃~0.5℃、0.5℃~1.0℃、0.2℃~ −0.5℃；成熟至收获期日较差提高了−0.9℃~0.6℃；出苗率、株高、茎粗、棒穗长、每棒穗粒数、千粒重分别比(CK1)提高了−3.3~3.4百分点、−16.7~−3.5 cm、−0.2~−0.3 cm、−2.7~0.0 cm、−33.7~−16.4粒、−17.3~−7.0 g；玉米产量12,664.5~14,493.0 kg/hm2，较CK1减产0.6%~13.1%，说明四种生物可降解地膜和普通地膜对玉米产量影响差异不大，较CK2增产86.3%~113.1%，产量差异达极显著水平。四种生物可降解地膜的覆盖率，玉米收获时分别为25.8%、64.3%、24.4%和51.5%，至翌年玉米播种时分别为3.3%、7.4%、6.2%和16.5%，说明四种生物可降解地膜的降解特性基本符合北方高海拔灌区玉米生长对环境的要求，完全可以替代传统地膜。 Biodegradable plastic film is an important way to solve the problem of plastic film residue pollu-tion. It has great potential for agricultural development, but different biodegradable plastic films were different in different ecological regions and affected its popularization and application. In this paper, comparative field experiments were carried out among three cultivation methods, 9 biodegradable films cultivation, ordinary PE (CK1) film cultivation and open field cultivation (CK2), from field degradability of plastic film, soil thermal insulation, crop growth, yield and its composition factors, residual plastic film coverage and so on. The result showed that the degradation of the selected four kinds of biodegradable plastic films GS05, GS09, GS10 and GS03 was slow at the early growth stage of maize and quicker in the middle and later stages, and the growth adaptability of maize was better. The soil temperature in the whole maize growth period at 10 cm soil layer from emergence to jointing stage, from tasseling to filling stage compared to CK1, decreased from 0.1˚C to 0.5˚C, from 0.5˚C to 1.0˚C and from 0.2˚C to 0.5˚C. The difference of maturity from harvest to maturity was improved by −0.9˚C - 0.6˚C. Emergence rate, plant height, stem diameter, panicle length, grain number perpanicle, 1000-grain weight compared to CK1 increased by −3.3 - 3.4 percentage points, −16.7 to −3.5 cm, −0.2 to −0.3 cm, −2.7 to 0.0 cm, −33.7 to −16.4, −17.3 to −7.0 g; maize yield was 12,664.5~14,493.0 kg/hm2, which was 0.6~13.1% less than that of CK1. The results showed that the effect of four biodegradable mulches and ordinary mulching film on maize yield was not significant, which was 86.3% - 113.1% higher than that of CK2, and the difference was significant. The coverage of the four kinds of biodegradable mulching films was 25.8%, 64.3%, 24.4% and 51.5% respectively when corn was harvested, which was 3.3%, 7.4%, 6.2% and 16.5%. These results indicated that the degradation characteristics of the four biodegradable plastic mulch basically accorded with the environmental requirements of maize growth in the high elevation irrigation area of northern China, and could replace the traditional mulching film.