Effect of zinc amended fertilizer on yield, microbial quantity and respiration of the cultivated soil of Chinese kale production

Abstract

This study aimed to investigate the effect of different fertilization among organic fertilizer or organic-chemical fertilizer amended with 3 level of Zn 0, 0.5 and 1% on growth, yield and Zn content of Chinese kale (Bang Bua Thong 35). The field experiment was conducted in Bangkuwat, Muang, Pathumthani during February to April 2023 with an experimental design of 2x3 factorial in completely randomized design (CRD). The different fertilizers were applied at 3^rd fertilization to the 30-day-old-Chinese kale. Growth parameters and fresh mass yield were collected at a time of harvesting (44 days) and then the vegetables were tested for Zn content using AAS. Results exhibited that Zn amended fertilizer provided negative effects on plant height and fresh yield for approx. 28%, however, consequent Chinese kale accumulated greater amount of Zn for approx. 22%. The highest yield (9.2 kg/m²) obtained from the co-application of chemical fertilizer and organic fertilizer (1:1) at a rate of 40 g/m^-2, while, maximum Zn content in the kale obtained when co-applying of chemical fertilizer and either 1%Zn amended organic- or 0.5-1% Zn amended organic chemical- fertilizer which provided total Zn content of 89.8 and 91.8-98.1 mg/kg Dw, respectively. Moreover, it was found that Zn amended fertilizer provided no effect on total number of soil microorganisms. Nevertheless, the application of 1% Zn organic-chemical fertilizer exhibited a reduction of Zn solubilizing microorganisms after 3 days applying, and then recovered later after 7 days applying. Additionally, the soil respiration rate and soil chemical properties seemed to be slightly affected.