Soil nutrient characteristics in vineyards with different planting ages inthe suburb of Shanghai

Abstract:【Objective】Grape is one of the four major fruits that planted in Shanghai and plays a very im⁃portant role in agricultural production and economic outputs in this municipality. Soil nutrient status, akey factor that impacts grapevine growth and grape yield and quality, is generally governed by fertilizermanagement practices. The objective of this study is to explore the soil nutrient status and characteristicsin vineyards in Shanghai suburb, which were still unknown. Vineyards with different planting ages wereselected to analyze soil nutrient characteristics. The results will be helpful for formulating scientific fertil⁃ization in vineyards and for sustainable development of grape industry in Shanghai.【Methods】67 vine⁃yards in the suburb of Shanghai were selected for this study and classified into 3 groups based on theirplanting ages, i.e. 1-5 year, 6-10 year and >10 year. 10 soil samples were collected in each vineyard atsites scattered in an“S”form. ASI (Agro Services International Inc.) analysis method developed by the International Agrochemical Service Center in Florida, was adopted to analyze the soil nutrient characteris⁃tics. Soil chemical properties and nutrient contents including soil organic matter (OM), soil pH and theavailabilities of N, P, K, Ca, Mg, S, Fe, Cu, Mn, Zn and B were evaluated. The data were used to evaluatethe impacts of different planting ages on soil nutrient characteristics.【Results】Soil OM content in vine⁃yards decreased in the first 10 year planting period and increased after 10 year of cultivation, but no signif⁃icant difference was observed among the vineyards in the 3 age groups. Soil available N increased in thefirst 10 year planting period, and then decreased after 10 year of cultivation. Soil available N in the 6-10year vineyards was significantly higher than in the 1-5 year vineyards, but had no significant differencecompared to vineyards >10 year. The average soil available N in vineyards of 1-5 year, 6-10 year and >10 year vineyards was 75.41 mg·L^-1,123.99 mg·L^-1 and 71.49 mg·L^-1, respectively. Soil available P and Kboth increased along with grape planting ages. The average soil available P in vineyards of 1-5 year, 6-10year and >10 year was 118.30 mg·L^-1, 114.13 mg·L^-1 and 172.98 mg·L^-1, respectively, while the averagesoil available K was 256.33 mg·L^-1, 325.31 mg·L^-1 and 425.60 mg·L^-1, respectively. The highest availableP and K contents both appeared in the >10 year vineyards and was significantly higher than in the other 2groups. The highest soil available Zn content was observed in >10 year vineyards with 20.00 mg·L^-1. Thehighest soil available B appeared in 6-10 year vineyards with 2.75 mg·L^-1. No significant differenceswere observed among different vineyards in the other soil nutrients (available Ca, Mg, S, Fe, Cu and Mn).Soil pH tended to decrease with grape planting ages, but no significant difference was observed among dif⁃ferent planting ages. The average soil pH values in the 1-5 year, 6-10 year and >10 year vineyards were7.01, 6.79 and 6.57, respectively, indicating soil acidification might have occurred in some vineyards afterlong term cultivation.【Conclusion】Significant impacts of planting age on soil available N, P, K, Zn and Bcontents were observed in this study. However, no clear correlation was observed between grape plantingage and soil OM storage, soil pH and other soil micronutrients contents. After long term cultivation, themajority of soil nutrient contents in vineyards showed positive correlation with grape planting age, whilesoil pH was negatively correlated with grape planting age. The results indicate that planting age is a keyfactor that regulates soil nutrient characteristics in vineyards. According to the ASI analysis method andgrading standard, most of the soil nutrients in vineyards in of Shanghai were at high or extra-high levels.Thus, the fertilizer application rates, especially those of P and K fertilizers should be reduced in the pres⁃ent vineyards in Shanghai suburb, which could enhance the utilization efficiency of the fertilizers and soilnutrients. In addition, more organic fertilizer should be applied to maintain sufficient soil OM storage. Scientific fertilization methods according to soil nutrient status could save a lot of agricultural production input and improve soil acidification conditions.