低丘红壤花生南酸枣间作系统研究IV.光能竞争与剪枝作用

农林间作导致间作花生区域光合有效辐射和花生产量的下降，而且花生产量与光合有效辐射呈极显正相关，表明了光能竞争是导致农林间作花生产量下降的主要原因。2001年6月初剪枝后，5龄和9龄南酸枣间作系统花生相对光合有效辐射分别从5月份的79．2％和63-4％增加到88．7％和67．5％；但随着南酸枣生长，5龄和9龄南酸枣间作系统中7月份的花生相对光合有效辐射又下降到80．8％和65．7％。2001年剪枝以后，5龄南酸枣和9龄南酸枣间作系统花生相对产量分别由2000年的64．1％和55．4％提高到68．2％和58．1％。这表明剪枝在短期内能在一定程度上减轻光能竞争，但仍然不能满足花生生长需要。

CHOEROSPONDIAS AXILLARIS AND PEANUT (ARCHIS HYPOGAEA) ALLEY CROPPING SYSTEMS ON UDIC FERROSOL IN SUBTROPICAL CHINA IV. COMPETITION FOR LIGHT AND ROLE OF TREE PRUNING

Competition for light was one of the key factors for decline in peanut yield in agro-forest alley cropping systems, since lower PAR of the peanut rows and peanut yield was found in the alley cropping system than that, respectively, in the peanut mono-cropping system, and peanut yield is correlated significantly to PAR. After tree pruning in early June 2001, relative PAR index of the peanut crops was increased to 88.7% and 67.5% from 79.2% and 63.4% in May in the 5-year-old and 9-year-old Choerospondias axillaris alley cropping systems, respectively. However, with the trees growing, it was slowly decreased to 80.8% and 65.7% in the two systems in July, respectively. After tree pruning, relative peanut yield was increased to 68.2% and 58.1% in 2001 from 64.1% and 55.4% in 2000 in the two systems, relatively, which indicated that tree pruning may mitigated slightly competition for light in a short period, but it couldn''t meet the demand of peanut for light during its growing period.