Soil phosphorus dynamics and availability and irrigated coffee yield

Abstract

SUMMARYResearch data have demonstrated that the P demand of coffee (Coffea arabica L.) is similar to that of short-cycle crops. In this context, the objective of this study was to evaluate the influence of annual P fertilization on the soil P status by the quantification of labile, moderately labile, low-labile, and total P fractions, associating them to coffee yield. The experiment was installed in a typical dystrophic Red Latosol (Oxisol) cultivated with irrigated coffee annually fertilized with triple superphosphate at rates of 0, 50, 100, 200, and 400 kg ha -1 P 2 O 5 . Phosphorus fractions were determined in two soil layers: 0-10 and 10-20 cm. The P leaf contents and coffee yield in 2008 were also evaluated. The irrigated coffee responded to phosphate fertilization in the production phase with gains of up to 138 % in coffee yield by the application of 400 kg ha -1 P 2 O 5 . Coffee leaf P contents increased with P applications and stabilized around 1.98 g kg -1 , at rates of 270 kg ha -1 P 2 O 5 and higher. Soil P application caused, in general, an increase in bioavailable P fractions, which constitute the main soil P reservoir.Index terms: Coffee arabica L., phosphate fertilization, phosphorus fractionation.(1) Received for publication in May 2010 and approved in January 2011.

Microbiological properties and oxidizable organic carbon fractions of an oxisol under coffee with split phosphorus applications and irrigation regimes

“…The P content in these soils is generally well below the critical level, around 8 mg dm -3 , for clay soils (Sousa & Lobato, 2004;Reis et al, 2011). This limits crop growth, requiring the application of corrective fertilizer, in view of the high P demand of coffee for fruit production and the rapid initial growth (Nazareno et al, 2003).…”

“…Thus, in an attempt to maximize P uptake, the supply in split doses is associated to the most demanding development stages of the crop (flowering, growth and grain filling), since, according to studies of Reis et al (2011) and Silva et al (2010), P application increases yield, dry matter production and growth of coffee plants.…”

Yield gains of coffee plants from phosphorus fertilization may not be generalized for high density planting

“…The high yields obtained may also be considered (mean yield of the four crop seasons of 64 bags/ha of hulled coffee, 2.7 times greater than the mean value of the Zona da Mata of the State of Minas Gerais), a strong indication that P was not a limiting factor under these conditions. Although some studies report an effect of phosphate fertilization applied during the production period on coffee yield (Prezotti & Rocha, 2004;Reis et al, 2011), in general, a large increase in the yield of adult woody plants is not expected as a result of P supply in this phase (Novais et al, 1982), as observed in this study and in the studies of Figueiredo et al (2006) The nutrient, P, is one of the macronutrients least accumulated by the coffee plant (Corrêa et al, 1986). Thus, responses of this plant to phosphate fertilization, when they occur, are due to the low availability of this nutrient in the soil, and may furthermore vary as a result of greater or lesser uptake efficiency and/ or efficiency in utilization of the nutrient by the plant, regulated by genetic and environmental factors (Novais & Smyth, 1999;Pozza et al, 2009;Amaral et al, 2011).…”

“…Another example is the study of Reis et al (2011), in which there was a great response of the adult irrigated coffee plant to the addition of P. In that study, P availability was very low and the soil showed high capacity for fixing this element (P-Mehlich-1was 3.3 and 1.4 mg dm -3 , and residual P was 4.5 and 4.3 mg L -1 in the 0-10 and 10-20 cm layers, respectively). Moreover, for comparison to this study, the effect of irrigation and the fact of the crop being in different climate conditions from those of the Zona da Mata of the State of Minas Gerais should be taken into consideration.…”

“…Nevertheless, studies have shown expressive responses to the addition of this nutrient in some producing regions (Gallo et al, 1999;Reis et al, 2011). Even so, it might not be possible to extrapolate the conclusions and/or recommendations obtained to other growing regions, given the diversity of environments and management conditions of the crop.…”