Phosphate Sources and Their Placement Affecting Soil Phosphorus Pools in Sugarcane

Valdevan Rosendo Dos Santos,André Vitti,Oriel Kolln,Amin Soltangheisi,Paulo Pavinato,Henrique Junqueira Franco,Carlos Santos Dias

doi:10.3390/agronomy8120283

Abstract

Phosphate fertilizer placement at sugarcane (Saccharum spp.) establishment can strongly influence the distribution of soil P pools over crop cycles, and has a great influence in the availability of this nutrient to plant uptake. Our main objective was to evaluate sugarcane yield as well as changes in the distribution of soil P pools, under phosphate fertilizer sources and their management, over two years of sugarcane cultivation. The experiment was established in August 2013 with two phosphate sources (TSP (triple superphosphate) and RP (Bayovar rock phosphate)) and three application methods: as broadcast, at planting furrow and combining half broadcast/half plant furrow, all at the rate of 180 kg ha−1 soluble P2O5 being applied at crop establishment. Sugarcane yield and P uptake was evaluated, and soil was sampled after harvest in August 2015 to analyze P fractions. Substantial amounts of P derived from fertilizers were accumulated as inorganic and/or organic moderately labile P. Broadcast application of TSP was not able to enhance total P in 0–40 cm layer compared to control treatment. In general, TSP was more effective to supply P for sugarcane and keep more of this nutrient in all labile fractions in the soil. However, the potential residual effect of RP (Ca-P) is expected in the following years, slowly solubilizing over the time.

Highlights

IntroductionIt is the world’s largest producer of sugar and accounts for one-third of the global production of bioethanol [1]
Cane yield was significantly improved by P fertilizer sources used at establishment
Phosphorus uptake by sugarcane under TSP in all all application methods and rock phosphate (RP) applied as broadcast and B + F were higher than control treatment application methods and RP applied as broadcast and B + F were higher than control treatment and and RP in planting furrow (Figure 2B)

Summary

Introduction

It is the world’s largest producer of sugar and accounts for one-third of the global production of bioethanol [1]. It is estimated that a further 6.4 Mha of new sugarcane area will be required to meet the Brazilian demand for ethanol by 2021 [1]. This additional land will primarily come from areas currently in degraded pasture [3], which are classified as low yield environments because of their acid soils, low natural fertility and low phosphorus (P) availability [4].

Objectives

Methods

Results

Discussion

Conclusion