Residual phosphorus effects and nitrogen × phosphorus interactions in soybean–maize rotations on a P-deficient Ferralsol uri icon

abstract

  • Legume-cereal rotations are an essential component of integrated soil fertility management in low-input cropping systems, but strategies are needed to increase phosphorus (P) fertilizer use efficiency in such systems. These may include preferential targeting of P to one of the crops in the rotation cycle, the use of P-efficient genotypes, and the optimization of the rates of P fertilizer used. A field trial was conducted to evaluate the effects of increasing P fertilizer rates (0, 11, 22 and 44 kg P ha(-1), added as triple super phosphate) applied to three soybean genotypes grown on a P-deficient Ferralsol, on the nitrogen (N) and P nutrition of a subsequent maize crop. In addition, a greenhouse trial was set up to assess N, P and other rotation effects of three soybean genotypes on a subsequent maize crop relative to a maize-maize rotation at high and low P supply. In the field trial, soybean did not respond to increasing P rates, but residual P effects improved maize grain yields by up to 90 %. Ear leaf (field trial) and shoot (pot trial) P concentrations increased by applying N to maize, demonstrating important N x P interactions. The pot trial did not reveal a positive rotation effect of soybean on maize beyond the mere N-benefit, showing that soybean was not able to improve P availability to maize after correcting for the N-effect. No variation in rotation effects on maize among soybean genotypes was observed. Because of the absence of effects of the soybean crop on P availability to maize, opportunities to increase P fertilizer use efficiency in soybean-maize rotations mainly reside in maximizing P uptake by each crop separately and in matching P fertilizer rates with crop demand.
  • Legume-cereal rotations are an essentialcomponent of integrated soil fertility management inlow-input cropping systems, but strategies are needed toincrease phosphorus (P) fertilizer use efficiency in suchsystems. These may include preferential targeting of Pto one of the crops in the rotation cycle, the use ofP-efficient genotypes, and the optimization of the ratesof P fertilizer used. A field trial was conducted toevaluate the effects of increasing P fertilizer rates (0, 11,22 and 44 kg P ha-1, added as triple super phosphate)applied to three soybean genotypes grown on a P-deficientFerralsol, on the nitrogen (N) and P nutrition of asubsequent maize crop. In addition, a greenhouse trialwas set up to assess N, P and other rotation effects ofthree soybean genotypes on a subsequent maize croprelative to a maize?maize rotation at high and low Psupply. In the field trial, soybean did not respond toincreasing P rates, but residual P effects improvedmaizegrain yields by up to 90 %.Ear leaf (field trial) and shoot(pot trial) P concentrations increased by applying N tomaize, demonstrating important N 9 P interactions.The pot trial did not reveal a positive rotation effect ofsoybean on maize beyond the mere N-benefit, showingthat soybean was not able to improve P availability tomaize after correcting for the N-effect. No variation inrotation effects onmaize among soybean genotypes wasobserved. Because of the absence of effects of thesoybean crop on P availability to maize, opportunities toincrease P fertilizer use efficiency in soybean?maizerotations mainly reside in maximizing P uptake by eachcrop separately and in matching P fertilizer rates withcrop demand

publication date

  • 2014
  • 2014
  • 2014