Low fertilizer inputs do not adversely affect yield or performance of Indica hybrid rice

Zhiyuan Huang,Lihuang Zhu,Longping Yuan,Zhaohui Wu,Fangjun Tan,Yeyun Xin,Md Amir Hossain,Qiming Lv,Yulin Peng

doi:10.1590/1678-992x-2020-0402

Abstract

The enhancement of rice production numbers can be achieved by using quality rice cultivars and fertilizers. The double rice cropping model has given rise to an important rice production system in southern China. Exploring the possibility of whether hybrid vigor could make a substantial contribution to early and late season rice production, and how the heterosis expression of hybrid rice functions under different levels of fertilizer application is of great significance. The objective of this study was to evaluate the grain yield and associated plant traits of popular hybrid and inbred rice varieties with large–scale promotion under conditions of customary (high) and combined (low) fertilization in the early and late seasons of 2017–18 in Changsha County, Hunan Province, China. We found that hybrid rice varieties displayed their respective advantages in the early and late rice seasons, but the advantages in their relative yield traits varied. The leading advantages of early season rice were effective panicle number per hill (EPN), 1000–grain weight (KGW), harvest index (HI), yield, and nitrogen use efficiency (NUE), whereas in late season rice, the foremost advantages were grain number per panicle (GNP), HI, yield, and NUE. The EPN was the prime advantage of early season hybrid rice with a short growth period, and the GNP was the main advantage of late season hybrid rice with a long growth period. Notably, the main yield advantage of hybrid rice was stronger under combined (low) fertilization than under customary (high) fertilization. Hence, high yield can be achieved by selecting the best hybrid rice varieties supported by combined fertilization (lower fertilizer use with higher efficiency).

Highlights

Rice (Oryza sativa L.) is one of the most important food crops, accounting for 25 % of China’s total planted area and 37 % of its national cereal production
The effective panicle number per hill (EPN) was the prime advantage of early season hybrid rice with a short growth period, and the grain number per panicle (GNP) was the main advantage of late season hybrid rice with a long growth period
biomass accumulation per hill (BPH) and plant height (PH) are independent of fertilizer regimen and cultivar across seasons Source capacity is typically expressed as a unit of biomass production, which directly relates to the photosynthetic capacity of plants (Zhang et al, 2009)

Summary

Introduction

Rice (Oryza sativa L.) is one of the most important food crops, accounting for 25 % of China’s total planted area and 37 % of its national cereal production. It is of great importance to explore whether hybrid vigor could substantially contribute to early and late season rice production and how the heterosis expression of hybrid rice functions under different fertilization conditions. In addition to the maintenance of agricultural growth and increase in yield and harvest, combined fertilization has advantages of both convenience of use and reduced environmental pollution (Li, 2018). Many farmers select hybrid rice to increase yield, the performance of early and late season hybrid rice has not been clarified under different fertilization conditions. The objectives of this study were to (1) evaluate the performance of hybrid rice in double cropping seasons, and (2) identify the effects of different fertilization treatments on heterosis expression

Objectives

Methods

Results

Discussion

Conclusion