黄土高原新造耕地施用羧甲基纤维素钾的土壤效应

Effects of Application of Potassium Carboxymethyl Cellulose on Soil Water and Nutrients in Newly Cultivated Farmland

【目的】基于黄土高原新造耕地土壤质量改良需求,开展以羧甲基纤维素钾(CMC-K)为土壤改良剂的田间定位试验研究,为新造耕地土壤水分保持与养分改良提供依据。【方法】设置CK(0 kg hm^(-2))、T1(100 kg hm^(-2))、T2(500 kg hm^(-2))、T3(1000 kg hm^(-2))和T4(2000 kg hm^(-2))5个处理,对不同处理的新造耕地土壤水分、电导率与养分进行了测定与分析。【结果】新造耕地施用CMC-K土壤含水量提高14.6%~121.7%,在谷子生长季前期(6月和7月)和后期(10月)土壤保水功效较大。在CMC-K较高施用量(1000~2000 kg hm^(-2))情况下,谷子生长季前期(6月)土壤电导率提高了37.3%~73.4%;全部处理在谷子生长季后期(10月)的土壤电导率显著降低,降低幅度达19.2%~21.8%;谷子生长季的土壤电导率呈现降低趋势。施用CMC-K能够提高土壤硝态氮9.6%~46.5%、速效磷21.9%~207.9%和速效钾13.2%~95.9%,对土壤pH基本没有影响。施用CMC-K谷子产量提高了6.2%~19.2%。【结论】施用CMC-K能够保持土壤水分,促进养分吸收利用,提高谷子产量,可以作为黄土高原新造耕地土壤改良剂使用,推荐施用量约100 kg hm^(-2)。

[Objective] Based on the requirement of soil water and nutrient improvement of newly cultivated farmland of Loess Plateau in Yanan, Shaanxi Province, potassium carboxymethyl cellulose(CMC-K) was acted as a soil amendment. [Method] The field experiment was conducted with 5 treatments( CK, 0 kg hm^(-2) T1, 100 kg hm^(-2) T2,500 kg hm^(-2) T3, 1000 kg hm^(-2) T4, 2000 kg hm) to research the changes in soil water, soil electric conductivity and soil nutrients. [Result] CMC-K application improved soil water content 14.6%-121.7% in newly cultivated farmland,the efficacy of CMC-K application was better in early(June and July) and end-stage(October) of millet growing season than those in the middle stage(August and September). The large CMC-K application amounts(1000-2000kg hm) could improve significantly soil electric conductivity by 37.3%-73.4% in early(June) of millet growing season, and soil electric conductivities of all treatments were decreased significantly by 19.2%-21.8% in end(October)of millet growing season. Soil electric conductivities presented decreasing trend in the millet growing season. CMC-K application had no effects on soil total nitrogen, total phosphorus, total potassium, and pH, but enhanced soil nitrate(9.6%-46.5%), available phosphorus(21.9%-207.9%), and available potassium(13.2%-95.9%). CMC-K application could increase millet yield by 6.2%-19.2%. [Conclusion] CMC-K application can hold soil water, promote soil nutrient absorption and raise millet yield in newly cultivated farmland in Loess Plateau, which may act as a soil amendment and the recommended application rate is 100 kg hm.