黄淮海平原农林生态系统N、P、K营养元素循环——以泡桐-小麦、玉米间作系统为例

N, P and K recyclings in an agroforestrial ecosystem of Huanghuaihai plain: with Paulownia elongata-intercropped wheat and maize as an example.

农林生态系统泡桐-小麦、玉米间作类型N、P、K营养元素循环研究表明,在整个群落中,P发生亏损,N和K基本平衡;在植物组分库和枯落物库中,N、P、K均发生累积;在土壤库中,N、P、K均发生亏损。土壤表层(0—20cm)中N和P的含量是限制农作物生长的主要因子。20—80cm土层中P的含量是限制泡桐生长的主要因子。群落内N、P、K的吸收系数分别为0.078、0.014、0.052,利用系数分别为0.95、0.90、0.94,循环系数分别为0.042、0.05、0.063.

The studies show that in the whole community, P is deficient, and N and K are basically balanced. N, P and K are accumulated in plant tissues and litters, but depleted in soil. N and P contents in surface soil(0-20cm) are the main factors affecting crop growth, and P content in 20-80cm soil layer in the major one affecting Paulownia elongata growth. The absorption coefficients of N, P and K in the communities are respectively 0.078, 0.014 and 0.052, their utilization coefficients are respectively 0.95, 0.90 and 0.94, and their recycling coefficients are respectively 0.042, 0.05 and 0.063.