Supplementation of P-solubilizing purple nonsulfur bacteria, Rhodopseudomonas palustris improved soil fertility, P nutrient, growth, and yield of Cucumis melo L.

Abstract The study was aimed to evaluate the efficacy of supplying a mixture of four phosphorus (P)-solubilizing purple nonsulfur bacteria strains, Rhodopseudomonas palustris VNW64, VNS89, TLS06, and VNW02 (P-solubilizing purple nonsulfur bacteria (PS-PNSB)) on soil properties, P uptake, growth, and yield of canary melon (Cucumis melo L.). The experiment consisted of eight treatments, including 100% P (150 kg P2O5 ha−1) as recommended, 75% P, 50% P (75 kg P2O5 ha−1), and no fertilizers, and these treatments with adding PS-PNSB mixture. The results showed that supplying the PS-PNSB mixture had improved the soil pH and the available P content. Moreover, fertilizing 100% P with the mixture of the four PS-PNSB strains resulted in the greatest P uptake (7.88 kg P ha−1). However, interestingly, when supplying 75% P with the PS-PNSB mixture, the P uptake was 6.11 kg P ha−1 and was statistically equal to the 100% P treatment (5.87 kg P ha−1). This could be found in other parameters. Therefore, supplying the PS-PNSB mixture can be claimed to reduce 25% P, but still maintain plant height, fruit length, fruit perimeter, and yield of canary. In addition, supplying the PS-PNSB mixture contributed to a 5.26–9.42% increase in the canary melon yield among P fertilizer rates. Based on the aforementioned results, the PS-PNSB mixture in the current study should be further commercialized and transferred for farmers’ use to enhance the yield of canary melons and reduce the rate of chemical fertilizers for the ultimate goal of sustainable agriculture. Graphical abstract