<b>Effects on soil chemical attributes and cotton yield from ammonium sulfate and cover crops

Abstract

ABSTRACT. Fertilizer use in no-till systems must be aligned with a correct interpretation of soil chemical attributes and crop demands. The objectives of this work were evaluate the effects of pre-sowing application of ammonium sulfate (AS) and of cover crops on the yields and soil chemical attributes of no-till cotton (Gossypium hirsutum L. r. latifolium Hutch) over two harvesting years. The experiment was arranged in randomized complete block design, with the plots in strips, and the variables were three cover crops (Raphanus sativus L., Avena strigosa L. and Avena sativa L.) and four AS doses (0, 150, 300, and 450 kg ha -1 ) applied over millet dry biomass. The cotton in the experimental plots was manually harvested on April 25, 2007 and April 24, 2008. The soil samples were collected between cotton rows in all plots on May 5, 2007 and May 12, 2008, at depths of 0.0-0.05, 0.05-0.10, and 0.10-0.20 m for soil fertility analyses. The increasing doses of AS induced lower soil pH, and calcium (Ca) and magnesium (Mg) levels in the superficial soil layer, as well as higher exchangeable aluminum (Al) and sulfur (S) levels until a depth of 0.20 m. Seed cotton yields increased with increasing AS doses.Keywords: Gossypium hirsutum, fertilizer management, soil fertility, no-till.Efeito nas características químicas do solo e produtividade do algodoeiro em função de sulfato de amônio e plantas de cobertura RESUMO. A adubação no sistema plantio direto deve ser aliada a uma correta interpretação das características químicas do solo e necessidade das culturas. O trabalho objetivou avaliar em dois anos de cultivo, o efeito da aplicação de sulfato de amônio (SA) em pré-semeadura do algodoeiro e de plantas de cobertura, implantadas em semeadura direta, sobre atributos químicos do solo e produtividade do algodoeiro. O delineamento experimental foi o de blocos ao acaso, disposto em faixas, compostos por três plantas de cobertura (nabo forrageiro, aveia preta e aveia branca); e 4 doses de adubação nitrogenada (0, 150, 300 e 450 kg ha -1 de sulfato de amônio), aplicadas sobre a palhada do milheto. A colheita das parcelas experimentais do algodoeiro foi manual em 25/04/07 e 24/04/08. Em 05/05/07 e 12/05/08 foram coletadas amostras de solo nas profundidades de 0,0-0,05; 0,05-0,10 e 0,10-0,20 m, na entrelinha do algodoeiro para caracterização da fertilidade. O aumento de doses de sulfato de amônio reduziu os valores de pH, e teores de Ca e Mg na superfície do solo, bem como aumentou a concentração de Al + trocável e de enxofre até 0,20 m. A produtividade de algodão em caroço aumentou com as doses de sulfato de amônio.Palavras-chave: Gossypium hirsutum, manejo da adubação, fertilidade do solo, plantio direto.

Phosphorus release dynamics under phosphate rock and ammonium sulphate in soil amendment

“…In other studies, Fageria et al (2010) and Ferrari et al (2015) also found the soil pH to decrease with increasing doses of AS fertilizer rates. Ammonium sulphate is an acidic reaction fertilizer and it is stated that it will increase the microflora and Soxidizing bacteria in the soil as a sulphur containing fertilizer, thus accelerating the pH decrease (Lluch and Olivares, 1979;Müftüoğlu and Sarımehmet, 1993).…”

Chemical Characteristics of the Use of Gelatine Sludge in Soil Cultivated as Fertilizer

“…An opposite effect was verified when comparing these results with the literature. For example, ammonium sulphate was found to cause a reduction of pH, calcium and magnesium with an increase of the aluminum content (Ferrari et al, 2015). Vol.…”

Controlled and Prolonged Release Systems of Urea from Micro‐ and Nanomaterials as an Alternative for Developing a Sustainable Agriculture: A Review

“…Industries have been producing large quantities of nitrogen fertilizers, such as ammonium sulfate, ammonium nitrate, NPK (nitrogen, phosphorus, and potassium), and urea, mainly [27][28][29][30]. However, the most used fertilizer worldwide nowadays is urea due to its high nitrogen content (46%), high solubility, easy application, and its easy production (Figure 1) [6,26,29,31]. Urea is manufactured through a heterogeneous reaction that results in dehydrated urea, which is marketed as granular urea or conventional urea by the agrochemical industries [30,32,33].…”