Mineralization of Nitrogen Forms in Soil Cultivated with Yellow Melon under Organic and Mineral Fertilization

Abstract

ABSTRACT The association of mineral and organic fertilization is a nitrogen supply system for the melon crop. Nitrogen (N) fractionation is an important tool to understand its dynamics in the soil and the contribution of each fraction to N bioavailability. This study aimed to evaluate the effects of organic and mineral fertilization on organic and inorganic forms of soil N of the cultivation of yellow melon. The experiment was conducted in the Experimental Field of Pacajus, belonging to Embrapa Agroindústria Tropical, in soil classified as Red Yellow Argisol. The experimental design was a split-plot randomized block. Fertilizer application was the main plot treatment and sampling time was arranged as subplots. The experimental results indicated that only organic fertilization was sufficient to significantly increase the total-N content (varying from 1,127 mg kg−1 to 967 mg kg−1) compared to only mineral fertilization (951 mg kg−1) and organic N represented 92 ± 2% of the total-N. In addition, the higher hydrolyzable N content was observed in the treatment with only bovine manure application (542 mg kg−1) which represents an N source for the mineralization and subsequent inorganic N for plants. Our results reveal that organic fertilization is efficient for long-term fertility management, increasing melon productivity.