残膜对农田土壤养分含量及微生物特征的影响

发布时间：2018-06-30 19:14

本文选题：残膜 + 土壤肥力　；参考：《中国农业科学》2017年02期

【摘要】：【目的】探究残膜对土壤养分含量和生物学特征的影响,明确产生危害的土壤残膜强度限值,为中国残膜污染防治工作提供理论支撑。【方法】于2011—2015年在甘肃张掖设置0(CK)、150 kg·hm~(-2)(T1)、300 kg·hm~(-2)(T2)、450 kg·hm~(-2)(T3)以及600 kg·hm~(-2)(T4)残膜梯度试验,并测定不同残膜强度下土壤理化性状、微生物量碳氮、微生物群落丰度以及土壤酶活性等关键指标。【结果】残膜对土壤含水量、有机质(SOM)、全氮(TN)、铵态氮(NH_4~+-N)、硝态氮(NO_3~--N)、有效磷(Olsen-P)的影响较大,随着残膜强度的增加,土壤含水量显著增加(P0.05),而SOM、TN、NO_3~--N以及Olsen-P显著降低(P0.05),NH_4~+-N则表现出先升高后降低的变化趋势。低残膜强度下,土壤微生物量碳(MBC)和土壤微生物量氮(MBN)含量增加,但高残膜强度(T3和T4)则会显著降低土壤微生物量(MBC和MBN)及微生物群落丰度(吸光值平均变化率、丰富度、Shannon指数、Simpson指数以及Mc Intosh指数)(P0.05)。土壤酶活性随残膜强度的变化趋势同微生物量碳氮含量基本一致,残膜强度为300—450 kg·hm~(-2)时,土壤中α-葡萄糖苷酶(AG)、β-葡萄糖苷酶(BG)、纤维素酶(CBH)、木聚糖酶(BXYL)以及几丁质酶(NAG)活性普遍较高,残膜强度为600 kg·hm~(-2)时土壤酶活性显著降低(P0.05)。【结论】农田土壤中低量残膜存在下可通过保水作用提高土壤微生物活性及其丰富度,而当残膜强度超过450 kg·hm~(-2)时,土壤微生物量、微生物群落丰度和土壤酶活性显著降低;同时,长期残膜作用下会降低土壤SOM、TN、NH_4~+-N、NO_3~--N以及Olsen-P含量,引起土壤养分退化。因此,对于中国地膜残膜污染较严重的地区,应加大残膜防治工作力度,降低残膜引起的土壤退化风险。
[Abstract]:[objective] to investigate the effects of residual film on soil nutrient content and biological characteristics, and to determine the limit of soil residual film strength. [methods] from 2011 to 2015 in Zhangye, Gansu Province, 150 kg hm-2 (T1) and 300 kg hm-2 (T2) of 450kg hm-2 (T3) and 600kg hm-2 (T4) residual film gradient tests were set up in Zhangye, Gansu Province, from 2011 to 2015, and soil physical and chemical properties, microbial biomass carbon and nitrogen were measured. [results] soil moisture, organic matter (SOM), total nitrogen (TN), ammonium nitrogen (NH4- N), nitrate nitrogen (NO3 N), available phosphorus (Olsen-P) were significantly affected by residual film, and with the increase of residual film strength, the soil water content, organic matter (SOM), total nitrogen (TN), ammonium nitrogen (NH4- N), nitrate nitrogen (NO3 N) and available phosphorus (Olsen-P) were significantly affected by residual film. Soil water content increased significantly (P0.05), while SOMN TNNO3-N and Olsen-P decreased significantly (P0.05) NH4- N increased first and then decreased. Under low residual film intensity, soil microbial biomass carbon (MBC) and soil microbial biomass nitrogen (MBN) content increased, but high residual film strength (T3 and T4) significantly decreased soil microbial biomass (MBC and MBN) and microbial community abundance (absorptivity average change rate). Richness: Shannon index Simpson index and MC Intosh index (P0.05). The change trend of soil enzyme activity with residual film strength was basically consistent with microbial biomass carbon and nitrogen content, when the residual film strength was 300-450 kg hm ~ (-2). The activities of 伪 -glucosidase (AG), 尾 -glucosidase (BG), cellulase (CBH), xylanase (BXYL) and chitinase (nag) were generally high in soil. The soil enzyme activity decreased significantly when the residual film intensity was 600 kg hm-2 (P0.05). [conclusion] in the presence of low residual film, the soil microbial activity and its richness can be improved by water retention, but when the residual film intensity exceeds 450 kg hm ~ (-2), the soil microbial biomass can be increased. The abundance of microbial community and the activity of soil enzyme decreased significantly, and the soil nutrient degradation was caused by the effect of long-term residual film on soil SOMN, NH4 ~ -N, NO3 N and Olsen-P contents. Therefore, in China, the residual film pollution should be increased to reduce the risk of soil degradation caused by residual film.
【作者单位】：中国农业科学院农业资源与农业区划研究所/农业部面源污染控制重点实验室;甘肃省农业科学院;甘肃省农业科学院土壤肥料与节水农业研究所;
【基金】：国家公益性行业(农业)科研专项(201003014)
【分类号】：S158;S154.3

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