The Optimal Cultivar × Sowing Date × Plant Density for Grain Yield and Resource Use Efficiency of Summer Maize in the Northern Huang–Huai–Hai Plain of China

Lichao Zhai,Junjie Ji,Xiuling Jia,Mengjing Zheng,Jingting Zhang,Lihua Zhang,Bo Ming,Ruizhi Xie,Haipo Yao

doi:10.3390/agriculture12010007

Abstract

In order to explore the optimal cultivar × sowing date × plant density for summer maize (Zea mays L.) in the Northern Huang–Huai–Hai (HHH) Plain of China, field experiments were conducted over two consecutive years (2018–2019) on a loam soil in the Northern HHH Plain. A split–split plot design was employed in this study, and the main plots included three cultivars (HM1: early-maturing cultivar; ZD958: medium-maturing cultivar; DH605: late-maturing cultivar); subplots consisted of three sowing dates (SD1: June 10; SD2: June 17; SD3: June 24); sub-sub plots include two plant densities (PD1: 6.75 × 104 plants ha−1; PD2: 8.25 × 104 plants ha−1). The results showed that the effects of cultivar and plant density on grain yield of summer maize were not significant, and the sowing date was the major factor affecting the grain yield. Delayed sowing significantly decreased the grain yield of summer maize, this was due mainly to the reduced kernel weight, which is associated with the lower post-anthesis dry matter accumulation. Moreover, radiation use efficiency (RUE), temperature use efficiency (TUE), and water use efficiency (WUE) were significantly affected by cultivar, sowing date, and plant density. Selecting early- and medium-maturing cultivars was beneficial to the improvements in RUE and TUE, and plants grown at earlier sowing with higher plant density increased the RUE and TUE. The interactive analysis of cultivar × sowing date × plant density showed that the optimum grain yields of all tested cultivars were observed at SD1-PD2, and the optimum RUE and TUE for HM1, ZD958, and DH605 were observed at SD1-PD2, SD2-PD2, and SD2-PD2, respectively. The differences in the optimum grain yield, RUE, and TUE among the tested cultivars were not significant. These results suggested that plants grown at earlier sowing with reasonable dense planting had benefits of grain yield and resource use efficiency. In order to adapt to mechanized grain harvesting, early-maturing cultivar with lower grain moisture at harvest would be the better choice. Therefore, adopting early-maturing cultivars grown with earlier sowing with reasonably higher plant density would be the optimal planting pattern for summer maize production in the Northern HHH Plain of China in future.

Highlights

A growing body of research indicates that climate change has adverse effects on crop production [1,2], which poses a great challenge to food security worldwide [3,4]
The interactive analysis of cultivar, sowing date, and plant density showed that the maximum grain yield (GY) for all tested maize cultivars were obtained at SD1-PD2, with the exception of Zhengdan 958 (ZD958) in 2018, and the maximum GYs of Huamei 1 (HM1), ZD958, and Denghai 605 (DH605) was not significantly different from each other
ANOVA revealed that the effects of cultivar, sowing date, and plant density on yield components were significant in most cases (Tables 2 and 4)

Summary

Introduction

A growing body of research indicates that climate change has adverse effects on crop production [1,2], which poses a great challenge to food security worldwide [3,4]. The frequent heat stress resulted by warming climate has been the most important contributor in reduced maize grain yields [6,7], especially in the Northern HHH Plain. Optimizing culture and management practices to adapt the local summer maize production is urgently needed. Selecting adapted maize cultivars is an effective way to cope with some of the adverse effects of climate change [8,9,10]. Some previous studies suggested that adapted latematuring maize cultivars could effectively offset the negative impacts of a warming climate on crop productivity [10].

Methods

Results

Discussion

Conclusion