Carrot yield and water-use efficiency under different mulching, organic fertilization and irrigation levels

Daniel F De Carvalho,Dionizio H De Oliveira Neto,José G M Guerra,Daniela P Gomes,Janaína R C Rouws,Fábio L De Oliveira

doi:10.1590/1807-1929/agriambi.v22n7p445-450

Abstract

ABSTRACT This study was carried out to evaluate the contributions to the optimization of water use in a carrot crop under different forms of mulch using Gliricidia sepium, fertilization with castor bean cakes and irrigation water depths. The experiment was conducted in Seropédica, RJ, Brazil (22º 46’ S and 43º 41’ W), from June to September 2010. The experiment was conducted using a split-split-plot scheme (5 x 3 x 2), with four replicates. The five plots had irrigation depths corresponding to 0, 43, 72, 100 and 120% of crop evapotranspiration (ETc); the three subplots contained the different forms of mulch (whole leaves (WL) and chopped leaves and branches (CLB)) and the absence of mulch (AM); and the two sub-subplots contained either the presence (PF) or absence of fertilization (AF). Using time domain reflectometry (TDR) in the irrigation management, water depths ranging from 67.8 to 285.5 mm were applied. The use of mulch in association with fertilization led to higher yields and water-use efficiency (WUE) of the carrot plants, and the mulch composed of WL performed best. The application of irrigation depths corresponding to 97% of ETc promoted the highest carrot yields, although the highest values of WUE were observed, with irrigation depths corresponding to a range from 51 to 68% of ETc.

Highlights

Carrots (Daucus carota L.) are one of the most consumed vegetables in the world, and they are the root vegetable with the highest economic value in Brazil (Resende et al, 2016)
In addition to controlling the amount of water applied, appropriate management of fertilizer positively affects the production of roots, especially in organic agricultural systems, which are needed to ensure the availability of nitrogen (N) to achieve adequate yields (Dawson et al, 2008)
With the application of 100% of the crop water requirement (244.4 mm), no significant differences were observed between the types of mulch independent of fertilization, but the presence of fertilization (PF) provided the highest total yield in the absence of mulch (AM)

Summary

Introduction

Carrots (Daucus carota L.) are one of the most consumed vegetables in the world, and they are the root vegetable with the highest economic value in Brazil (Resende et al, 2016). In addition to controlling the amount of water applied, appropriate management of fertilizer positively affects the production of roots, especially in organic agricultural systems, which are needed to ensure the availability of nitrogen (N) to achieve adequate yields (Dawson et al, 2008). The management practices employed in organic agriculture, such as the use of mulch and organic fertilizers, can increase the yield of crops without impacting production costs (Kang et al, 2008). These practices favor agricultural activities, which are characterized by a minimal use of external inputs and a limited amount of mineral fertilizers, on small properties (Egodawatta et al, 2012). Castor bean cake is another material that has been used as an organic fertilizer, and it has become an ideal option for meeting the nutritional requirements of crops (Lima et al, 2011)

Objectives

Methods

Results