Estado Nutricional De Sorgo Cultivado Sob Estresse Hídrico E Adubação Fosfatada

Abstract

O crescente aumento de áreas plantadas com sorgo (Sorghum bicolor (L.) Moench.), no Brasil, é evidência do seu potencial na alimentação animal. Esta forrageira apresenta produção de matéria seca mais elevada que o milho, especialmente em condições marginais de cultivo, como em solos de baixa fertilidade e locais onde a ocorrência de veranicos é frequente (Stone et al. 1996). Sua utilização, para a produção de silagem, também vem crescendo a cada ABSTRACT RESUMO ano, principalmente nas regiões onde esta cultura se sobressai (Souza et al. 2003). Caracteriza-se, ainda, por elevada tolerância ao estresse hídrico, fato que tem despertado, nos produtores, o interesse por esta cultura (Stone et al. 1996), constituindo-se em alternativa viável para a produção de forragem, em épocas que apresentam déficit de precipitação. O fósforo (P), essencial ao crescimento, desenvolvimento e à reprodução das plantas, está associado à fotossíntese, divisão celular e utilização de açúcares e amido (López-Bucio et al. 2002) e 1. Trabalho recebido em nov./2009 e aceito para publicação em jan./2011 (n° registro: PAT 8285/

Ionic Response and Sorghum Production under Water and Saline Stress in a Semi-Arid Environment

“…Furthermore, the response to water deficit of reducing shoot growth promotes root development, increasing the plant's resistance to water deficit [33][34][35]; therefore, this nutrient is more concentrated in the dry mass. Although researchers such as [36] have observed a reduction in K + in the aerial part of sorghum subjected to water stress, we understand that the different results found in this work can be explained by the fact that the K + evaluation was carried out directly from the diagnosis leaf.…”

Accumulation of macronutrients in cowpea and weeds in competition and under soil water deficit

“…J., Uberlândia, v. 35, n. 6, p. 1747-1757, Nov./Dec. 2019 http://dx.doi.org/10.14393/BJ-v35n6a2019-42432 SCHMIDHALTER, 2005); the reduction of root growth and its capacity on the macronutrients absorption and translocation, due possibly to process of root suberization (BARBERON et al, 2016) and the reduction of transpiration caused by the stomata closure in plants to minimize water losses (TANGUILIG et al, 1987); and increased mechanical impediment of dry soil for root growth, which limiting the volume of soil explored for nutrient acquisition (GARG, 2003;LEÃO;MIRANDA, 2011). The water deficit can also reduce the dry mass of plant (OLIVEIRA et al, 2018), and thus reduces the demand for nutrients.…”

“…The occurrence of competition with weeds by water can anticipate and/or intensify the deleterious effects of water stress due to low availability of water to plants (CRAINE; DYBZINSKI, 2013). Among these effects, it is possible to emphasize the reduction on the nutrient absorption and of quantities required by the plants (GONZALEZ-DUGO;DURAND;GASTAL, 2010;LEÃO;MIRANDA, 2011;DODD et al, 2015). Soil water deficit can reduce the absorption, accumulation, partition and nutrient utilization by plants, due to effect on the decrease of root growth, and by the fact that water is the vehicle through which the mineral nutrients move from the solution of soil to roots of plants, especially when this transport occurs by mass flow and diffusion, that is, all mechanisms of transport of nutrients in soil are affected (BARBER, 1974;MARSCHNER, 1995;HU;SCHMIDHALTER, 2005).…”