English

Abstract

To better understand the accumulation and transport of substances under different planting densities, the adaptation of maize root and leaf in response to increasing planting densities was investigated. In this two-year filed study, three maize varieties, Fumin108 (FM), Xianyu335 (XY) and Dika159 (DK), were sown under three different planting densities: 15,000 (D1), 60,000 (D2) and 90,000 plants ha-1 (D3) during 2018 and 2019. Increase in planting density gradually increased leaf area index along with reduced leaf area and net photosynthetic rate of individual leaves. In the 0–20 cm soil layer, the average root dry matter decreased by 55.88 and 80.92%, and the average root number decreased by 31.18 and 38.71% under D2 and D3, respectively, compared with D1. With increase in planting density, yield and dry matter per plant of maize gradually decreased while yield and dry matter per ha was increased with increase in D1-D2 density and then flattened in D2-D3 density. Compared with D1, two-year average yield per plant was decreased by 34.10 and 51.87% under D2 and D3, respectively. The difference in the number of roots of XY, FM and DK were not significant, so change in variety did not alleviate the decrease in the number of roots. At higher planting densities (above D2), the increase in density did not increase per ha grain yield. In conclusion, the suitable plant density was about 60,000 plants ha-1 to harvest more yield of spring maize while density higher than that reduced leaf area and photosynthesis per plant. Moreover, leaf area, root number and net photosynthesis per plant was higher in lower planting density coupled with overall less yield on ha basis and thus seemed wastage of soil nutrients and light resources. © 2021 Friends Science Publishers