Enhancing the qualitative and quantitative traits of potato by biological, organic, and chemical fertilizers

Sustainable agriculture is an integrated system based on ecological principles, providing society's present food needs, without compromising the ability for current or future generations to meet their needs. In this system, organic and biological fertilizers and bio-pesticides are used to maintain nutrients in the soil, control weeds and pests, and increase biodiversity. The present study aimed to evaluate some traits of Solanum tuberosum following the application of chemical, organic, and biological fertilizers. This study was conducted as a factorial experiment based on randomized complete block design in three replications in two agricultural years of 2017 and 2018. The first factor was chemical/organic fertilizers at five levels (No fertilizer, 100% Urea, 66% urea + 33% Manure, 33% urea + 66% Manure and 100% Manure) and the second factor was tuber inoculation with biological fertilizers at four levels (No bacteria, Azospirillum, Pseuidomonas, Azospirillum + Pseudomonas). The results showed that the combined application of Pseudomonas with 66% urea + 33% manure resulted in the highest protein (1861.6 kg/ha) and biological (140.69 t/ha) yields in the first year. While in the second year the highest biological yield (108.65 t/ha) was achieved by the application of Pseudomonas with 100% urea. The highest tuber protein content (7.05%) and nitrate content (93.45 mg/kg) were obtained by the application of Azospirillum + Pseudomonas with 100% manure in the second year. Although the positive effect of biological fertilizers, especially Pseudomonas, has been shown on potato characters, the use of biological fertilizers alone cannot completely replace the chemical fertilizers. Therefore, sustainable agriculture can be achieved by the implementation of integrated plant nutrition using urea, manure, and biofertilizers.