长期施肥对旱地红壤肥力和酶活性的影响

Effects of long-term fertilizer on soil fertility and soil enzyme activities in upland red soils

为了明确不同施肥种类对旱地红壤肥力与酶活性的影响,以30年(1981年至今)长期定位试验地为基础,研究不同施肥处理(CK,N,NP,NPK,2倍NPK,猪粪,NPK+猪粪)旱地红壤玉米田耕层(0～20 cm)土壤酶活性与养分的变化趋势及其相关性。结果表明:1)全N含量各处理间差异不显著,单施N肥显著增加土壤速效N,施有机肥处理(NPK+猪粪,猪粪)土壤的pH值、有机质、全P、速效P均显著增加;2)除了2倍NPK处理土壤脲酶活性最高外,施有机肥土壤的转化酶、脱氢酶、酸性磷酸酶、过氧化氢酶活性也较其他处理显著增加;3)酸性磷酸酶、过氧化氢酶、脱氢酶、脲酶与全N、有机质、速效N呈显著或极显著正相关;因此,红壤旱地通过长期施用有机肥或与无机肥配施,不仅能显著提高土壤肥力,而且能增加土壤酶活性,从而显著提高土壤持续生产力。

In order to understand the relation between soil enzyme activity and soil chemical propertities in upland red soil under different fertilizer treatments,we conducted a study to determine the effects of pig manure,inorganic fertiliser and combination of pig manure and inorganic NPK on soil chemical and biological properties in a more than 30 a long-term fertilization experiment.The treatments as the following：no fertilization（CK）,N,NP,NPK,double NPK,pig manure,NPK＋pig manure.The results showed,the total N content had no significant difference between different treatments.The only applied N could significantly improve available N in soil.Soil pH,organic matter,total P and available P in manure fertilization treatments（NPK＋pig manure and pig manure） all increased significantly compared with no fertilization（CK） and mineral fertilization treatmets（N,NP,NPK and double NPK）.Except for the highest urease activity was double NPK treatment,the soil invertase,dehydrognease,catalase and acid phosphatase activities were all significantly higher than those in other fertilization treatments.Acid phosphatase,catalase,dehydrognease and urease activities were significant and dramatically significant positively correlated with total N,organic matter and available N.So,manure application or co-application of manure and mineral fertilizers not only increased the soil fertility,but also enhanced significantly soil enzymes activities,thus could improve red soil sustainable productivity.