Nutrient cycling of different plant residues and fertilizer doses in broccoli cultivation

Ernane M Lemes,José Luiz R Torres,Valdeci Orioli Junior,Antônio Carlos Barreto,Fernando R da C Gomes,Guilherme Deodato França

doi:10.1590/s0102-0536-20210102

Abstract

ABSTRACT The decomposition and release of nutrients from plant residues that precede the cultivation of vegetables can positively affect the morphological parameters and crop productivity. The objective of this study was to evaluate the effects of plant residue decomposition and the cycling of macro and micronutrients of four cover crops preceding the broccoli production (single head Avenger hybrid). A 4x3 factorial scheme was implemented including four cover crops: signal grass (SG), pearl millet (PM), sunn hemp (SH), mixture PM+SH; and three doses of mineral fertilizer: 0, 50 (200 kg ha-1 of P2O5, 50 kg ha-1 of K2O, 75 kg ha-1 of N) and 100% of the recommended fertilizer dose (400 kg ha-1 of P2O5, 100 kg ha-1 of K2O and 150 kg ha-1 of N). Fresh (FB) and dry biomass (DB), residue decomposition, nutrient cycling of cover crops, the number of leaves, head height (HH), stem diameter (SD), head diameter (HD), head fresh-biomass (FB), head dry biomass (DB) and broccoli yield were evaluated. The FB production from PM (25.9 t ha-1), SG (23.3 t ha-1) and mixture PM+SH (23.9 t ha-1) were similar, while the largest production of DB occurred in the SG (11.9 t ha-1). The lowest rate of decomposition and the greatest half-life time of residues occurred where PM was present. The accumulation and nutrient cycling follow the sequence K>N>Ca>Mg>P>S and Mn>Zn>B>Cu for all cover crop treatments evaluated. The highest SD (51.95; 51.44 and 50.67 mm), HD (187.97; 187.41 and 183.48 mm), FB (1.01; 1.00 and 0.97 kg), DB (0.08; 0.07 and 0.07 kg) and broccoli yield (25.3; 24.9 and 24.7 t ha-1) was observed in the 100% dose of mineral fertilizer and on the residues of SH or PM+SH mixture, respectively.

Highlights

A decomposição e a liberação de nutrientes dos resíduos das plantas que antecedem o plantio direto das hortaliças podem afetar de forma positiva os parâmetros morfológicos e a produtividade da cultura
Vegetables such as those found in Horticultura Brasileira 39 (1) January - March, 2021 the Brassicaceae plant family are grown in a conventional farming method, with intensive tillage and use of high solubility fertilizers and agrochemicals (Torres et al, 2017)
This study aimed to evaluate the effects of cover crops plant residues on soil and nutrient cycling for the production of broccoli

Summary

Introduction

A decomposição e a liberação de nutrientes dos resíduos das plantas que antecedem o plantio direto das hortaliças podem afetar de forma positiva os parâmetros morfológicos e a produtividade da cultura. Broccoli can be consumed in natura and is prepared for consumption; in the Savannah (Brazilian Cerrado), due to high temperatures during most of the year, the production of broccoli is still a major challenge (Seabra Júnior et al, 2014) Vegetables such as those found in Horticultura Brasileira 39 (1) January - March, 2021 the Brassicaceae plant family are grown in a conventional farming method, with intensive tillage and use of high solubility fertilizers and agrochemicals (Torres et al, 2017). The no-tillage system of vegetable production reduces the dependence on fertilizers due to the maintenance, or increase, of the organic matter levels of the soil This increment occurs due to the biological nitrogen fixation from the Fabaceae plant family and by the cycling of macro and micronutrients contained in the residues from the different cover crops used (Assis et al, 2017; Pacheco et al, 2017). The implementation of the no-tillage system for broccoli production has the potential to reduce the use of mineral and agrochemical fertilizers (Doane et al, 2009)

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Results