Impact of Increasing Maize Densities on Agronomic Performances and the Community Stability of Productivity of Maize/Peanut Intercropping Systems

Yanfang Xue,Huasen Xu,Ruipeng Yu,Haiyong Xia,Jie Wang,Weilin Kong,Zhen Liu,Lan Wang,Xiaotong Guo,Xiaofeng Wang,Yanhui Xue

doi:10.3390/agronomy9030150

Abstract

Rational crop community structure plays an important role in maximizing the intercropping yield advantage. Effects of increasing maize densities in maize (Zea mays L.)/peanut (Arachis hypogaea L.) intercropping on yields and other agronomic traits, and the community stability of productivity were conducted across three different experimental sites. There were significant and positive correlations between maize densities and both maize grain/biomass yields and corresponding partial land equivalent ratios (LERs) across all three locations; but grain/biomass yields and partial LERs of peanut were all negatively correlated with maize densities in each or across all locations. LERs of grain yields averaged over three locations ranged from 0.89 to 0.98, while LERs of biomass yields ranged from 0.94 to 1.09 (>1.0 except for the maize inter-plant distance of 27 cm), indicating the intercropping advantage on biomass yields but not grain yields. Peanut had significantly lower kernel harvest indexes than those in monoculture. Excessive narrowing maize inter-plant distances reduced the community stability of productivity severely (especially for maize and total LERs) and are more likely to lead to abnormal maize and peanut plants. Therefore, a rational increase of maize densities in intercropping is suggested to keep the balance between maize and peanut and the comprehensive yield advantage.

Highlights

For the past two decades, scientists have hailed genetically modified (GM) crops and chemical fertilizer as the magic bullet that will solve the world’s food crisis [1]
Grain yields of maize calculated based on the total land area occupied by the whole intercropping system comprise by two crop species were decreased by intercropping with peanut at various maize inter-plant distances as compared to monoculture, especially for the experiment conducted in Dongying (Table 2)
Pearson correlation showed that the maize grain yields in intercropping were positively correlated with maize densities in the experiment conducted in Dongying (r = 0.701, n = 15, p ≤ 0.01) and across all three locations (r = 0.311, n = 45, p ≤ 0.05) (Table 3)

Summary

Introduction

For the past two decades, scientists have hailed genetically modified (GM) crops and chemical fertilizer as the magic bullet that will solve the world’s food crisis [1]. Intercropping systems play an important role in increasing crop quality and yield through efficient utilization of land, light, water and soil nutrients [6], and enhancing resilience to present and future climate change (the increase in global surface temperature and water scarcity) and pest, disease and weed damage [3,4]. It is defined as growing individuals of at least two crop species in close proximity at (about) the same time, always leading to harvest at least two different kinds of crop products and higher comprehensive economic benefits. Sustainable intensification of agriculture by intercropping is a new “Green Revolution” [7]

Methods

Results

Discussion

Conclusion