中文摘要：

分析了长期不同施肥处理下紫色土坡耕地土壤碳（C）、磷（P）与微生物生物量C（MBC）、P（MBP）的变化及其耦合特征.结果表明：农家肥或秸秆配施无机肥（包括N、NP和NPK）处理下紫色土坡耕地土壤总有机碳（TOC）变化范围为90.8-100.8 g·kg^-1,高于单施氮肥处理的62.2 g·kg^-1;农家肥与无机肥配施处理下土壤总磷（TP）变化范围为0.65-0.84g·kg^-1,而秸秆与无机肥配施处理下土壤TP仅为农家肥与无机肥配施的23%-38%;单施氮肥处理下MBP显著小于农家肥和秸秆与无机肥配施处理;农家肥和秸秆配施无机肥处理下MBC/MBP在5-26,TOC/TP分别在92-137和296-653,而单一氮肥处理下MBC/MBP和TOC/TP分别高达59和2000.表明农家肥和无机肥配施更有利于增加土壤P的有效性,提高土壤供P潜力.

英文摘要：

The aim of this study is to explore the changes and coupling characteristics of carbon （ C）, phosphorus （P） and microbial C, P in a hillslope cropland of purple soil. The results showed that total organic carbon （TOC） ranged from 90.8 to 100.8 g·kg^-1 under organic fertilizer or straw combined with inorganic fertilizer treatments （including N, NP and NPK） as compared with nitro- gen （N） application only （62.2 g·kg^-1）. Total phosphorus （TP） ranged from 0.65 to 0.84 g·kg^-1 in organic combined with inorganic fertilization treatments, and that under straw combined with inorganic fertilizer treatments was 23%-38% of organic fertilizer combined with inorganic ferti- lization treatments. The microbial biomass phosphorus （MBP） under N fertilizer was significantly decreased as compared with combined fertilization treatments. The ratios of microbial biomass carbon （MBC） to MBP under combined fertilization treatments were between 5 to 26, and the TOC/TP ratios under organic fertilizer and straw combined treatments were between 92 to 137 and 296 to 653, respectively, while those under N fertilizer treatment were 59 and 2000, respectively. The results indicated that combined organic and inorganic fertilizers would be helpful for enhancing. P availability and increasing its potential capacity in purple soil.