Nutrient use efficiency in alley cropping systems in the Amazonian periphery

Abstract

In the SE periphery of Brazilian Amazonia, low-input agriculture systems on sandy loam soils have very low nutrient use efficiency. In a low-input alley cropping system, we measured residue decomposition dynamics and the yield and nutrient uptake of a maize crop associated with the following treatments: Clitoria + Pigeon pea; Acacia + Pigeon pea; Leucaena + Clitoria; Leucaena + Acacia, Leucaena + Pigeon pea and no residue input (control). The acacia treatments provided better soil coverage throughout the whole corn cycle. Potassium was released faster than nitrogen from the residues; N concentration in corn leaves in the residue treatments were below critical levels. The Leucaena + Acacia treatment was the most effective in increasing posttasseling N and K assimilation and K use efficiency.This resulted in corn productivity 3.5 times greater (7.3 Mg ha −1 ) than the control without residue application. In the Amazonian sandy loam soils, which are susceptible to hardsetting and nutrient leaching, efficient N and K use should be priorities for soil management. Although no-till alley cropping of leguminous trees constitutes an important option for lowinput farming, its efficiency depends on using a mixture of residues that keeps soil covered and have high rates of both N and K release during the entire crop cycle.

Utilization and fate of phosphorus of different sources applied to cohesive soil of Amazonian periphery

“…Under leaching conditions, a steady release of N during the crop cycle from the residue is more important than rapid early availability in achieving high crop growth, according to Moura et al (2010). During the first year of our study, the SSP was more efficient than the ALP with or without the use of leucaena residue, which confirms that fertilizers containing more soluble P have a potential to supply P to plants immediately after application but that their P availability decreases over time (Rivaie et al, 2008).…”

Variabilidade espacial de atributos físico-químicos de um Latossolo Vermelho-Amarelo distrófico em sistema plantio direto

“…As baixas concentrações de matéria orgânica estão relacionadas ao tempo de implantação do sistema plantio direto (cinco anos), ainda não consolidado, por causa das condições ambientais nos trópicos que favorecem a rápida decomposição do material orgânico adicionado ao solo, dificultando o acúmulo de matéria orgânica, por mais que sejam adotados sistemas que a preservam (MOURA et al, 2010;GUARESCHI;PERIN, 2012).…”

Improving Farming Practices for Sustainable Soil Use in the Humid Tropics and Rainforest Ecosystem Health

“…Improving soil rootability conditions and increasing nutrient uptake by crops are crucial to overcoming the challenge of improving profitability and ecological sustainability in a large area of the humid tropics [17]. Unfortunately, under tropical conditions, the improved soil physical conditions that result from tillage are frequently short-lived due to the deterioration of the porous structure and the reconsolidation of the soil at the rootable layer [16].…”

“…Unlike in other regions of Brazil, the sole use of inorganic potassium (K) and nitrogen (N) fertilizers is not recommended here because it does not allow a crop to reach its greatest productivity potential [15]. Nutrient retention in the root zone can be enhanced where nutrients are added in a slow release form and biologically mediated processes are utilized for nutrient release, as with green manure [17]. These approaches may sustain agrosystems in the humid tropics better than saturating the soil solution with soluble nutrients [156].…”