Thermophosphate and organic fertilization in lettuce yield

Abstract

Organic fertilization is recommended for improving crop production. Lettuce has high nutrient uptake, so it demands soils with high fertility level. The aim of this study was to evaluate the effect of the thermophosphate addition to the chicken and cattle manure used for lettuce fertilization. The experiments were carried out under controlled environment following a randomized blocks experimental design with five replications. With the addition of the phosphorus in the chicken and in the cattle manure, there was an increase of the 64.96% and 23.52%, respectively in the yield. The concentration of nitrogen in the tissues was not affected by the addition of phosphorus in the mixtures. The NO₃^- concentration in the lettuce tissue was higher with the chicken manure treatment. The addition of thermophosphate to the chicken and the cattle manure had delayed the mineralization of nitrogen and balanced the forms of NH₄⁺ and NO₃^- in the soil and the tissues of the dry plants.