长期有机无机肥配施对陕南核桃林地土壤肥力质量的影响

比较长期有机无机肥配施对土壤化学及生物学性质的影响，综合分析评价土壤肥力质量，探索更加合理的配肥模式，为核桃施肥提供科学依据。共设置5种配肥模式:1）不施肥（CK）；2）单施化肥（T1）；3）化肥配施有机肥（T2）；4）化肥配施生物有机肥（T3）；5）化肥配施有机肥和生物有机肥（T4）。在核桃成熟期，对不同配肥模式下的土壤进行分层取样，测定0~60 cm土壤物理、化学及生物学指标，通过主成分分析对不同模式的土壤肥力质量进行评价。结果表明:1）T4处理的土壤全N、全P含量整体水平高于其他处理，在20~30 cm土层，T4处理的土壤有机质、硝态N、有效P、速效K含量最高，分别是CK处理的1.60、1.31、1.49、1.27倍（P＜0.05）；在50~60 cm土层，T1处理的土壤硝态N含量最高，较T4处理高了29.67%（P＜0.05）；在10~20 cm土层，T1处理的土壤铵态N含量最高，是CK处理的1.43倍（P＜0.05）；在20~30 cm土层，T4处理的土壤pH显著低于其他处理，在30~40 cm土层，T4处理的土壤EC值最高，是CK处理的1.11倍（P＜0.05）。2）在5~40 cm土层，T4处理的土壤微生物量N、C显著高于其他处理（P＜0.05）。4）在0~5、5~10 cm土层，各处理土壤肥力质量得分为正，且高于下层；T4处理的土壤肥力质量综合得分整体水平高于其他处理。化肥配施有机肥和生物有机肥可显著增加土壤有机质含量，并可增加土壤微生物量，提高土壤的整体养分水平，防止N素损失及P、K的固定，具有提高土壤肥力质量的作用。

Effects of Long-Term Combined Application of Organic and Inorganic Fertilizers on Soil Fertility Quality of Walnut Forest in Shannan Region

To compare the effects of long-term combined application of organic and inorganic fertilizers on soil chemical and biological properties; to comprehensively analyze and evaluate soil fertility quality; and to explore more ideal fertilization patterns,so as to provide more suitable basis for walnut fertilization.There were 5 types of combined fertilization models,including no fertilizer (control ),chemical fertilizer (T1),chemical fertilizer with organic fertilizer (T2),chemical fertilizer with biological organic fertilizer (T3),chemical fertilizer with organic fertilizer and biological fertilizer (T4).During the walnut maturity period,the soil samples under different fertilization types were collected layer by layer,the physiochemical and biological indicators of 0-60 cm soil layer were measured,and the soil fertility quality under different types was analyzed by principal component.1) The overall levels of total nitrogen,total phosphorus of T4 were higher than other treatments.In the soil layer of 20-30 cm,organic matter,nitrate nitrogen,available phosphorus and available potassium contents of T4 treatment were the highest,which were 1.60,1.31,1.49,1.27 times of the control,respectively (P＜0.05); in soil layer of 50-60 cm,T1 treatment had the highest nitrate nitrogen content,which was 29.67% higher than T4 treatment (P＜0.05); in soil layer 10-20 cm,T1 treatment had the highest ammonium nitrogen content,which was 1.43 times of the control (P＜0.05); in soil layer of 20-30 cm,soil pH of T4 treatment was significantly lower than other 4 treatments,in soil layer of 30-40 cm,and soil EC of T4 treatment was the highest,which was 1.11 times of the control (P<0.05).2) In the soil layer of 5-40 cm,the soil microbial biomass nitrogen and carbon of T4 treatment were significantly higher than other 4 treatments (P<0.05).3) In the soil layers of 0-5,5-10 cm,soil fertility quality scores of each treatment were higher than the beneath layers; the overall soil quality score of the T4 treatment was higher than other 4 treatments.The combined application of chemical fertilizer,organic fertilizer and bio-organic fertilizer has significant effects on increasing soil organic matter content,increasing soil microbial biomass,improving soil nutrient levels,and preventing nitrogen loss and phosphorus and potassium fixation,and improving soil fertility quality.