Soil fertility characteristics and their influencing factors in tea plantations of Jiangxi Pro-vince, China

Abstract

To investigate soil fertility status and characteristics of typical tea plantations, we selec-ted 372 typical tea plantations of 21 areas across Jiangxi Province and analyzed the soil nutrient, spatial data, and their correlations with topography, soil type, elevation and plantation age. The results showed that soil pH, organic matter, alkaline nitrogen, available phosphorus, available potassium, total nitrogen, total phosphorus and total potassium of tea plantation in Jiangxi reached 53.9%, 60.1%, 56.1%, 22.9%, 38.5%, 43.7%, 11.1% and 95.5% of indices of high fertility, high efficiency and high yield tea plantation, respectively, with the available phosphorus showing a strong variation. Soil available copper, zinc, iron, manganese and boron reached 76.3%, 74.2%, 96.8%, 73.1% and 0.0% of the first-class standards for soil trace elements, respectively. Tea plantations with highest soil fertility located in central Jiangxi, followed by northeastern and northwestern Jiangxi, and lowest in southern Jiangxi. Soil pH was significantly positively correlated with organic matter, alkaline nitrogen, available phosphorus, available potassium, total nitrogen and total phosphorus but not for total potassium. For different topography, soil fertility was highest in the flat land, followed by the high mountains, and lowest in the mountains and hills. Across different soil types, soil fertility was higher in paddy soil, sandy soil and mountain yellow brown soil, followed by yellow soil, red-yellow soil and purple soil, and lowest in red soil. Soil pH, organic matter and total potassium increased while available phosphorus decreased with altitude. The organic matter, alkaline nitrogen, available phosphorus, total nitrogen and total phosphorus increased, but soil pH decreased with time. In summary, soil fertility of tea plantations in Jiangxi Province was generally good, with high organic matter, total potassium, available copper, zinc, iron and manganese. However, soil was acidic, available phosphorus and total phosphorus content was low, available boron was seriously limited. We suggest increase soil pH and potassium supply in central Jiangxi, increase potassium and nitrogen fertilizer supply in northeastern Jiangxi, increase organic matter and phosphorus fertilizer supply in northwestern Jiangxi, and increase nitrogen, phosphorus and potassium supply combined with organic fertilizers in southern Jiangxi. High mountain tea plantations should enhance available phosphorus and potassium supply. Mountain tea plantations should enhance nitrogen and phosphate supply. Tea plantations with red and yellow soil should increase pH and total potassium supply. Tea plantations with red soil should apply nitrogen, phosphorus and potassium fertilizers combined with organic fertilizers. Tea plantations with yellow soil and mountain yellow brown soil required additional phosphorus supply, and tea plantations with purple soil should increase soil organic matter supply. Tea plantations need to increase dolomite powder, physiological alkaline fertilizers and organic fertilizers to prevent soil acidification.