Effects of Corn Monoculture and Intercropped with Medicago sativa L.on Corn Yield and Nutrient Contents of Albic Soil under Different N Levels

WANG Shuai; WANG Libo; LI Yuxi; LIU Lingyun; CHEN Dianyuan; WANG Nan; ZHUANG Wei

doi:10.15933/j.cnki.1004-3268.2018.02.005

Abstract：To reveal the advantage role of corn intercropped with Medicago sativa L.in the improvement of Albic soil fertility and enhancement of corn yield,four different N levels (140,175,200,225 kg/ha) were set,the effects of corn monoculture and intercropped with Medicago sativa L.based on the form of 2-0 culture on the corn yield and the contents of total N,organic matter and available nutrients in Albic soil were studied.The results showed that under the same cultivation mode,the corn yield was enhanced with the increase of N level.Under the same N level,the corn intercropped with Medicago sativa L.had an advantage over the corn monoculture in terms of increasing corn yield.Based on the corn monoculture, with the increase of N level,the peak of total N content was advanced to the tassel stage from the mature stage,the organic matter content was shifted from consumption to accumulation;undert the maximum N level (225 kg/ha),the loss of alkaline N reached the most.Based on intercropped with Medicago sativa L.,the alkaline N content could be enhanced to the peak value in the tassel period;compared with the jointing period,the N application could increase the organic matter content of Albic soil except the treat-ment with N of 200 kg/ha could make the organic matter content decreased by 12.0%;175 kg/ha N was more beneficial to reduce the loss of alkaline N after the corn harvest;when the application level of N (140 kg/ha) was minimum,the corn intercropped with Medicago sativa L.could increase the loss of total N,and with the increase of amount of N,the corn intercropped with Medicago sativa L.could relieve the loss of total N content of Albic soil.When the N levels were 140,175,200 kg/ha,the corn intercropped with Medicago sativa L.could alleviate the loss of organic matter content of Albic soil from the jointing pe-riod to the tassel stage;when the N level was 225 kg/ha,the corn intercropped with Medicago sativa L. could make the organic matter content increased by 13.9% compared with corn monoculture treatment. No matter corn monoculture or intercropped with Medicago sativa L.could increase the loss of available P and K contents of Albic soil in every growth period,among which the available K content was decreased first and then increased with the growth period of corn;the applied N level of 175 kg/ha or 200 kg/ha could make the available P content accumulated under the corn monoculture and intercropped with Medi-cago sativa L.respectively;affected by the corn intercropped with Medicago sativa L.,the applied N of 175 kg/ha could greatly promote the loss of available K,and when the applied N level being decreased to 140 kg/ha,the available K content could be accumulated to the greatest extent.To sum up,under the same N level,the corn intercropped with Medicago sativa L.was more advantageous than corn monoculture in raising corn yield;the high N level could effectively alleviate the loss of total N content of Albic soil from the corn intercropped with Medicago sativa L.,and simultaneously increase the contents of organic matter and available P.In this mode,the applied N amount of 175 kg/ha could minimize the loss of avail-able N and promote the loss of available K furthest.