Variations in soil water replacement levels promote changes in forage cactus mineral composition and biomass productivity

Abstract

Population growth and the need to exploit natural resources to produce food and guarantee food sovereignty reduce water availability, which can influence nutrient absorption capacity and production of plants. This study evaluated whether variations in soil water replacement levels promote changes in the mineral composition and biomass productivity of forage cactus varieties. A field experiment was conducted in a randomized block design with five levels of reference evapotranspiration replacement (25, 50, 75, 100 and 125% ETo) and three replicates. Contents of the macronutrients N, P, K, Ca, Mg and S; micronutrients Cu, Fe, Mn, Zn, Cl, Na and B; and biomass productivity were quantified in two varieties of forage cactus (‘Orelha de Elefante Mexicana’ and ‘Miúda’). The data were subjected to principal component and multivariate variance analysis. The mineral composition of the forage cactus varieties ‘Miúda’ and ‘Orelha de Elefante Mexicana’ can be optimized from soil water management, so as to obtain adequate nutritional balance for higher yield. The replacement level of 75% ETo promoted greater balance between nutrients in the cladodes of the forage cactus variety ‘Miúda’, while ‘Orelha de Elefante Mexicana’ had better nutritional balance with the replacement levels of 100 and 125% ETo. Soil water replacement levels of 100 and 125% ETo promote high accumulation of Na+ and Cl- ions in the cladodes of the forage cactus varieties studied. Highest biomass productivity of the varieties ‘Orelha de Elefante Mexicana’ and ‘Miúda’ was obtained with 75 and 100% ETo replacement levels, respectively. Among the varieties, ‘Orelha de Elefante Mexicana’ had a higher capacity for nutrient accumulation and biomass productivity, followed by ‘Miúda’, under the edaphoclimatic conditions of the Brazilian semiarid region.

Técnicas de Manejo Sustentável para o Aporte Forrageiro da Agricultura Familiar no Semiárido Brasileiro: Palma Forrageira, Irrigação e FonDren

“…Para o semiárido, essa variabilidade climática vem provocando alterações no calendário agrícola de várias culturas, principalmente daquelas cultivadas corriqueiramente em condições sequeiro, promovendo mudanças na data de semeadura e na forma de execução de técnicas de manejo (Lima et al, 2020). Previsões indicam que o semiárido brasileiro terá um aumento de 1°C na média de temperatura do ar e redução de 20% na precipitação pluviométrica até o ano de 2040 (Lacerda et al, 2015).…”

“…A literatura descreve como o uso da irrigação maximiza a produtividade da palma forrageira (Araújo Júnior et al, 2021;Azevedo Júnior et al, 2019;Campos et al, 2021;Diniz et al, 2017;Ferraz et al, 2020;Fonseca et al, 2019;Queiroz et al, 2016;Silva et al, 2020b). Na Tabela 1, é possível observar os recentes projetos com palma forrageira associando a produtividade ao uso da irrigação.…”