EFEITOS DA FERTIRRIGAÇÃO E DA ADUBAÇÃO CONVENCIONAL NA SALINIDADE E NO pH DOS SOLOS EM CULTIVOS SOB CONDIÇÕES DE AMBIENTE PROTEGIDO

• DOI: https://doi.org/10.22533/at.ed.3892402021

• Palavras-chave: Fertirrigação, Ambiente Protegido, Salinidade, pH do solo.

• Keywords: Fertirrigation, Protected Environment, Salinity, soil pH.

• Abstract: ABSTRACT: In the exploration of crops in a protected environment; mainly vegetable and small fruit crops face an increase in the salinity of these soils, given the reduced leaching of salts due to cultivation being carried out in covered environments; which prevents the leaching of excess fertilizers applied, there are those who have the main causes of this problem of salinization in Fertirrigation Practice, which is not true as it also occurs in conventional fertilization due to the fertilizers used having high saline levels. This work aimed to analyze salinity levels and soil pH before planting and at 30, 60 and 120 days of the cultural cycle of mini watermelon of the Sugar Baby variety grown under Fertigation compared to the same dose applied by Conventional Fertilization with 100 % of recommended dose. The work aimed to present viable technical solutions to resolve these salinization problems. In the study, soil samples were obtained from the 0-15 cm layers; 15-30 cm and 30-45 cm at 0, 30, 60 and 120 days. Salinity was found to be higher in treatments with fertigation in the shallower layers. Soil pH varied little depending on the forms of fertilization, sampled depths and sampling date. Salinity at a depth of 0-15 cm with conventional fertilization and a dose of 100% of the recommended dose were: 666 ds.m-1; 985 ds.m-1; 1012 ds.m-1 and 1295 ds.m-1 at 0, 30, 60 and 120 days of sampling, respectively. In treatments with fertigation they were: 764 ds.m-1; 1,077 ds.m-1; 1,478 ds.m-1 and 1,635 ds.m-1. In the 30-45 cm layer and conventional fertilization and a dose of 100% of the recommended dose were 420 ds.m-1; 512 ds.m-1; 536 ds.m-1 and 518 ds.m-1 . With fertigation carried out at the same depth and dose of 100% of the recommended fertilizer, the salinities were: 436 ds.m-1; 513 ds.m-1; 579 ds.m-1 and 695 ds.m-1 . The pH in the 0-15 cm layer with 100% conventional fertilization were: 7.35; 6.36; 7.10; and 6.89 at 0; 30; 60 and 120 days. With fertigation at the same depth and doses were: 7.38; 6.65; 6.92 and 7.37. At a depth of 30-45 cm with fertigation and a dose of 100% of the recommended dose, it was: 7.26; 6.69; 7.02 and 7.41. At a depth of 30-45cm they were 7.14; 6.78; 6.95 and 7.19. As a suggestion to minimize such problems, it is recommended that, before the construction of protected environments, drainage measures be adopted to allow, after each start of cultivation, the washing of these soils in stages subsequent to fertigation or conventional fertilization. Furthermore, use fertilizers with lower saline levels and greater solubilities to the detriment of others with these opposite characteristics.