液态地膜成膜与稳定机械性能研究

Film Forming and Stable Mechanical Properties of Liquid Mulching Film

为深入考察液态地膜在农业生产实际中应用的可行性和施用技术的合理性,探索液态地膜成膜与稳定机械性能变化规律及其影响机制,以商业液态地膜为研究对象,采用试验平台模拟实际田间成膜方法,利用万能材料物理试验机、食品物性分析仪等仪器,研究了液态地膜原浆液稀释比例、原浆液用量及土壤环境条件对液态地膜薄膜抗拉伸力和成膜稳定性的影响规律。结果表明:液态地膜的原浆液稀释比例、原浆液用量以及土壤环境条件均在不同程度上影响液态地膜成膜与稳定机械性能。其中液态地膜抗拉伸力随着原浆液稀释比例增加,呈现先增大后减小的趋势,当原浆液稀释比例为1∶4时,液态地膜薄膜的抗拉伸力达到最大值,此时拉断力为6.07N;当原浆液与水配比一定,液态地膜的抗拉伸力随着原浆液用量增加而逐渐增大,成膜稳定性也随之提高,然而过量的液态地膜浆液会吸附在成型的土壤团粒结构表面,待水分蒸发后形成独立膜体,不仅不能增强土壤团粒作用效果,反而给环境造成不必要的降解负担,因此推荐用量为45g·m^(-2),即450kg·hm^(-2);表层土壤颗粒度越小,喷施液态地膜后越容易把土粒粘结成小团块,增大土壤团粒间结合力,在土壤表层形成连续的地膜,显著提高土壤表面液态地膜成膜效果;同空白土壤样本相比,施用液态地膜土壤经模拟雨水浸泡后未出现明显干涸裂纹,进一步说明液态地膜施用可以有效地改善表层土壤团粒间结合力,保持土壤团粒结构稳定,提高土壤水稳定性和保墒效果。研究结果为液态地膜田间推广应用提供了理论支持和技术参考。

In order to investigate the application feasibility and reasonable application technology of liquid mulching film(LMF)in agriculture,and explore the film forming and stable mechanical properties of LMF,the stability,mechanical property and influence mechanism of the commercial LMF were investigated using laboratory simulation method.The influences of dilution ratio,dosage of concentrate and soil environmental conditions on the tensile stress and stability of LMF were studied by the universal material testing machines and food property analyzer.The results showed that the dilution ratio,dosage of the original solution and soil environmental conditions all had effects on the forming and stability of LMF.The tensile force of LMF increased first and then decreased with the concentrate dilution ratio increasing,with the maximum tensile force of6.07N in the concentrate dilution ratio of1:4.When the ratio of original slurry and water were fixed,the tensile force of LMF increased with the dosage of the original solution increasing.However,the excess LMF would adsorb on the surface of the soil pellet structure to form an independent membrane after evaporation,which would reduce the effect of soil granulation and cause unnecessary degradation burden on the environment.The recommended dosage was45g?m-2(450kg*hm-2);it was more easily to stick the soil particles into small clumps and form a continuous film on the surface of soil after reducing the soil granularity and increasing the binding force between soil aggregates,which could significantly improve the effect of film forming in soil surface.Compared with blank soil sample,the soil mulched with liquid film did not appear dry crack after rain soaked.This result further indicated that LMF can effectively improve the bonding force between surface soil aggregate,maintain soil granular structure stable and improve the effect of soil water stability and soil moisture conservation.The results would provide theoretical support and technical reference for the field application of LMF.