Effect of Amount of Irrigation and Type of P Fertilizer on Potato Yield and NH3 Volatilization from Alkaline Sandy Soils

Abstract

The choice of phosphate fertilizer has a special concern in alkaline soils due to its direct effect on the availability and uptake of phosphorus and micronutrients, as it can affect the rate of ammonia volatilization. This study aims to increase potato productivity in alkaline soils and reducing ammonia emissions by using acid fertilizers and controlling the amount of irrigation water. Two-year field trials were conducted in 2018 and 2019 growing seasons to investigate the influence of irrigation levels and P fertilizers on potato yield and ammonia volatilization from Arenosols. Potato (Solanum tuberosum, L.) cv Kara Spp. plants were irrigated at 75 or 100% of the evapotranspiration (ET75 and ET100) and were fertilized with monopotassium phosphate (MPP) or urea phosphate (UP), beside a control treatment without P addition. UP minimized the soil pH to 6.95 and 7.00 in the ET75 and ET100 treatments, respectively, compared to 7.80 and 7.85 in the case of MPP. The maximum potato tubers yield was achieved from ET100 and UP. The cumulative NH3 volatilization ranged between 33 and 85\xa0N\xa0kg\xa0ha−1 per season which was accounted for 12 to 27% of the total applied nitrogen. UP and ET100 minimized the N loss from 27 to 12%. Reducing the levels of added water increased the quality of tubers and efficiency of the added water, but it caused a significant loss in the total and marketable yield and elevated the rate of ammonia emissions from the calcareous sandy soils. The acidic P fertilizers are effective in reducing the ammonia loss and increase the availability of micronutrients.