羧甲基纤维素铵对黄土高原新造耕地土壤性质的影响

Effects of applying ammonium carboxymethyl cellulose on soil properties of new cultivated farmland in Loess Plateau

【目的】以羧甲基纤维素铵(CMC-NH 4)为土壤改良剂,分析其对陕西延安新造耕地土壤水分、电导率与养分的影响。【方法】在延安市安塞区,以谷子为供试作物,采用田间试验,设置CMC-NH 4施用量分别为0 kg/hm^(2)(对照,CK)、100 kg/hm^(2)(T1)、500 kg/hm^(2)(T2)、1000 kg/hm^(2)(T3)和2000 kg/hm^(2)(T4)5个处理,测定不同处理的土壤含水量、电导率和土壤养分(全氮、全磷、全钾、硝态氮、速效磷、速效钾)及pH,分析CMC-NH 4对谷子产量的影响,以及CMC-NH 4施用量与土壤理化性质和谷子产量的相关性。【结果】与对照相比,施用CMC-NH 4对土壤水分影响明显,可使土壤含水量提高15.2%~47.1%,且土壤含水量随着CMC-NH 4施用量的增加而增大。在7月和10月土壤含水量较低的情况下,CMC-NH 4各处理的土壤电导率均低于对照;在土壤含水量相对较高的情况下,如在谷子生长初期(06-28),CMC-NH 4施用量较高处理(T3和T4)的土壤电导率显著高于对照,在谷子生长中后期(08-30至09-23)CMC-NH 4各处理的土壤电导率与对照均无显著差异。施用CMC-NH 4总体可促进土壤养分的吸收利用,但对土壤pH无显著影响。施用CMC-NH 4总体能够促进谷子产量的增加,其中T1、T2和T4处理的产量较对照分别显著提高了12.8%,10.3%和10.2%,但T3处理与对照无显著差异。相关性分析表明,CMC-NH 4施用量与土壤含水量、硝态氮和全钾含量呈显著正相关关系,与其他指标相关性不显著。【结论】施用CMC-NH 4能提高延安新造耕地土壤水分,影响土壤养分与电导率,有助于提升土壤硝态氮和全钾含量,可以作为黄土高原新造耕地的土壤改良剂,推荐施用量为100 kg/hm^(2)左右。

【Objective】Ammonium carboxymethyl cellulose(CMC-NH 4)was used as a soil amendment and applied in new cultivated farmland in Yan’an,Shaanxi and its effects on water content,electric conductivity and nutrients of soil were analyzed.【Method】In Ansai district of Yan’an,millet field experiment was conducted with 5 treatments including 0 kg/hm^(2)(CK),100 kg/hm^(2)(T1),500 kg/hm^(2)(T2),1000 kg/hm^(2)(T3)and 2000 kg/hm^(2)(T4)to analyzed the effects of CMC-NH 4 on water content,electric conductivity,nutrients(total nitrogen,total phosphorus,total potassium,nitrate nitrogen,available phosphorus and available potassium)and pH of soil and millet yield.The correlations between CMC-NH 4 application amount and soil physical and chemical properties and millet yield were also analyzed.【Result】Applying CMC-NH 4 significantly increased soil water content by 15.2%-47.1%and it rose with the increase of CMC-NH 4 application rate.Soil electric conductivity of all treatments was less than that of CK in July and October when soil water content was low.Treatments with large application rates of CMC-NH 4(T3 and T4)improved soil electric conductivity to significantly higher than CK in early growing season of millet(June 28)when soil water content was sufficient.There was no significant differences in soil electric conductivity between treatments and CK in middle and end of millet growing season.Applying CMC-NH 4 promoted absorption of soil nutrients and affected soil pH.CMC-NH 4 application also generally improved millet yield,and yields of T1,T2 and T4 were significantly raised by 12.8%,10.3%and 10.2%.There was no significant difference between T3 and CK.Correlations between CMC-NH 4 application and soil water,nitrate and total potassium were positive and significant.【Conclusion】CMC-NH 4 application could improve water content,nutrients and electric conductivity of soil,and benefit soil nitrate and total potassium.CMC-NH 4 can be used as a novel soil amendment to new cultivated farmland in the Loess Plateau with recommended application rate of 100 kg/hm^(2).