GYPSUM AND PHOSPHORUS IN IMPROVING BIOMETRIC AND NUTRITIONAL ATTRIBUTES OF SOYBEAN/SECOND SEASON CORN SUCCESSION

Guilherme Filgueiras Soares,Carla Gomes Machado,Simério Carlos Silva Cruz,Darly Geraldo De Sena Junior,Tiago Camilo Duarte

doi:10.1590/1983-21252018v31n208rc

Guilherme Filgueiras Soares, Carla Gomes Machado + Show 3 more

Open Access

https://doi.org/10.1590/1983-21252018v31n208rc

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Abstract

ABSTRACT The objective with this work was to evaluate the effect of the agricultural gypsum, associated with phosphate fertilization, on the nutrition, development and yield of soybean and corn in succession, under no-tillage system. The experiment was conducted at Universidade Federal de Goiás, Regional Jataí, in a randomized blocks design 5x3 factorial arrangement, with 4 replicates. The first factor consisted of the gypsum doses (0, 1, 2, 4 and 8 Mg ha-1) and the second the phosphorus doses (0, 50 and 100% of the recommended dose). Leaf nutrient contents, leaf area index, SPAD index, dry plant mass, final plant population, one thousand grain mass and grain yield were evaluated in the crops. In the soybean, the number of pods was also obtained and in the corn the average ear length, number of rows per ear, number of grain per ear and number of ears. Phosphorus doses increase leaf Mg contents in soybean and corn. The application of gypsum reduces the Mg and K leaf contents and increases the Ca, S, and Mn contents in the two cultures. Gypsum provides increases in the SPAD index in soybean plants. The unbalance of the N / K ratio in corn leaves, provided by the increase of the gypsum doses, reduces the leaf area of this crop. Doses of P and gypsum do not influence the yield of soybeans and maize.

Highlights

As widely known, the productive potential of the cerrado soils is only reached due to the use of limestone that corresponds to an agricultural input that promotes pH correction and reduces soil toxic aluminum
This situation requires the use of soil conditioners, such as agricultural gypsum, to neutralize aluminum and provide calcium in depth (OLIVEIRA et al, 2009; ZANDONÁ et al, 2015)
Agricultural gypsum is a by-product of the phosphate fertilizer industry that mainly contains calcium sulfate and small concentrations of P and F (CAIRES et al, 2003; SÁVIO et al, 2011)

Summary

Introduction

The productive potential of the cerrado soils is only reached due to the use of limestone that corresponds to an agricultural input that promotes pH correction and reduces soil toxic aluminum. The sole use of this correction practice is strongly questioned since superficial liming without soil revolving (as recommended in the no-tillage system) limits the corrective effect of limestone to the superficial layers (CAIRES et al, 2003) This situation requires the use of soil conditioners, such as agricultural gypsum, to neutralize aluminum and provide calcium in depth (OLIVEIRA et al, 2009; ZANDONÁ et al, 2015). Agricultural gypsum is a by-product of the phosphate fertilizer industry that mainly contains calcium sulfate and small concentrations of P and F (CAIRES et al, 2003; SÁVIO et al, 2011) It is used as a source of Ca2+ and as a soil subsurface conditioner to reduce the toxicity of Al3+ (BROCH et al, 2008; OLIVEIRA et al, 2009)

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