Adubação de roseiras com base no balanço de nutrientes no sistema solo-planta

Abstract

Rose is an economically important crop for the national and the international market and due to this fact generates income to the Ceara State. Rose is a demanding crop in relation to fertilizers, requiring knowledge of soil fertility, nutritional plant requirements and nutrients use efficiency to obtain adequate fertilization. Based on the nutritional balance through the use of mechanistic and empirical models, it is possible to develop a system to quantify the plant nutrients demands to achieve a given productivity. This paper aims to establish parameters of a fertilizer and lime recommendation system to rose crop, based on the plant nutritional balance. The experiment was conducted at the company Cearosa in São Benedito - CE. Plants will be collected during five months and once a month, five rose plants from four varieties (Top Secret, Avalanche, Attache and Ambience) As contradictory Airlines plants Were grinded. Samples will be ground and nutrients content will be determined: N, P, K, Ca, Mg, S, B, Fe, Mn, e Zn. Every sampling plant time, were also soil samples collected at two depths (0-20 and 20-40 cm) In which they underwent fertility analysis. To estimate the fertilizer recommendation, the system was be subdivided into requirement subsystem (REQ), which includes the plant nutrients demands, considering the recovery efficiency of the nutrients to be applied and a rate to achieve the "sustainability" criteria and the supply subsystem (SUP) that comprises the soil nutrient supply. After determining the total REQ and SUP, held -if the nutritional balance, and if the result is positive (REQ> SUP), fertilizers application is recommended and if the result negative or zero (REQ ≤ SUP), fertilizers application is not recommended. The system estimated that there is excess nitrogen and phosphorus fertilization for all cultivars , however , there needs to be supplemental potassium fertilizer . The system estimated that the soil is able to meet the demand of plants for P and Fe for all cultivars , however , there must be supplementary nitrogen fertilizer , potassium . As for micronutrients , the system estimated that there is need for additional fertilizer for Zn in all rosebushes and Mn for the rosebushes "Top Secret " and " Avalnche " , however with very close recommendation the optimal dose , ie equal to zero.