Use of winter cover crops improves maize productivity under reduced nitrogen fertilization: a long-term study

Jonatas Thiago Piva,Djalma Eugênio Schmitt,Felipe Bratti,Jorge Luiz Locatelli,Marcos Renan Besen,Eduardo Brancaleoni,Ricardo Henrique Ribeiro

doi:10.1590/1678-4499.20200165

Abstract

ABSTRACT The objective was to evaluate the effect of winter cover crops on the agronomic performance of maize during five crop seasons in a clayey Inceptisol with reduced mineral nitrogen (N) inputs. The treatments were seven single cover crops: white oats (Avena sativa L.), black oats (Avena strigose Schreb.), ryegrass (Lolium multiflorum L.), canola (Brassica napus L.), vetch (Vicia sativa L.), fodder radish (Raphanus sativus L. and red clover (Trifolium pratense L.); a mix (black oats + vetch and a fallow. During summer, in succession to the cover crops, maize was grown under no-tillage. The attributes were evaluated in two stages of maize development: flowering (morphological components and physiological maturation (yield components). Differences in morphologica and yield variables were observed in all crop seasons, with emphasis on grain yield, number of grains per row (NGR and ear length (EL). The use of vetch showed greater contribution to the development of maize in relation to the other cover crops used, promoting an increase in stem diameter (SD), E and NGR in all crop season and directly reflecting in higher grain yield. On the other hand, when maize was grown under cover crops commonly used in southern Brazil, such as ryegras and white oats, the yield was similar to fallow. The results showed that vetch promoted higher maize yields, probably by N mineralization and reinforce the hypothesis that cover crops in the off-season can aggregate benefits to crops in succession, especially in terms of nutrition.

Highlights

Maize (Zea mays L.) is one of the pillars of Brazilian agribusiness
The results showed that vetch promoted higher maize yields, probably by N mineralization, and reinforce the hypothesis that cover crops in the off-season can aggregate benefits to crops in succession, especially in terms of nutrition
The maize yield and morphological parameters were influenced by cover crops along the crop seasons evaluated (Fig. 2 and Table 3)

Summary

Introduction

Maize (Zea mays L.) is one of the pillars of Brazilian agribusiness. With a cultivated area of ~ 17 million hectares in the 2018/2019 crop season, Brazil is the second largest exporter in the world (~ 29 million tons) (CONAB 2019; FAO 2019). The mean national productivity of 5,448 kg·ha-1 in the 2018/2019 crop season (CONAB 2019) is still below the productive potential that the crop presents and far from countries such as the USA, that registered an average productivity of 10,482 kg·ha-1 in the 2018/2019 crop season (USDA 2020) In this sense, the adoption of conservationist practices is necessary to maximize production in a safe, sustainable and low cost, being accessible to farmers. The adoption of conservationist practices is necessary to maximize production in a safe, sustainable and low cost, being accessible to farmers Alternatives such as the use of cover crops in the maize off-season can directly contribute to improve grain yield through the supply of nutrients, especially the nitrogen (N) (Balota et al 2014). The supply of N is extremely important for species of the grass family (Poaceae), as this is the nutrient most absorbed by maize and contributes more effectively to grain yield (Ribeiro et al 2018; Veloso et al 2018)

Objectives

Methods

Results

Conclusion