Is Foliar Nano-Urea an Effective Substitute to Soil Urea for Sustainable Peach Cultivation? Insights into Growth, Yield and Nitrogen Utilization
摘要
Excessive reliance on soil-applied urea in peach cultivation raises concerns regarding low nitrogen-use efficiency (NUE), yield sustainability and environmental impacts. Therefore, the study was aimed to evaluate the extent to which foliar nano-urea application may substitute the soil-applied nitrogen and improve nitrogen use efficiency (NUE) in peach cv. ‘Early Grande’. A two-year field experiment was conducted in a factorial randomized block design with four soil-applied nitrogen levels (100%, 75%, 50% and 25% RDN) and five foliar treatments (nano-urea at 0.01 g N L− 1, 0.1 g N L− 1, 1.0 g N L− 1, 0 g N L− 1 and 10 g N L− 1 as conventional granular urea), applied at the shucks-off stage. Growth, yield, yield-attributing traits, productivity and NUE were recorded. The combination of 100% RDN + 0.1 g N L− 1 significantly enhanced growth, fruit yield, productivity and NUE. Notably, 75% RDN + 0.1 g N L− 1 increased fruit yield and productivity by 19.35% and 19.37%, respectively, compared with the control (100% RDN + 0 g N L− 1). In contrast, reducing soil nitrogen to 50% or 25% RDN, either alone or in combination with nano-urea, resulted in marked reductions in growth, yield and NUE. Foliar application of nano-urea at 0.1 g N L− 1 can substitute up to 25% of soil-applied nitrogen without compromising peach orchard productivity. However, nano-urea cannot fully substitute soil-applied urea under low nitrogen conditions. An integrated nutrient management strategy combining 75% RDN with foliar nano-urea application at the shucks-off stage is therefore recommended for sustainable and efficient peach production.