Comparing C, N and P concentrations in soils in agricultural verus natural land, and across climates

Abstract: How do concentrations of C, N and P vary between agricultural and natural land?How do C, N and P concentrations vary between climate zones? Soil organic carbon (SOC),total nitrogen (TN) and phosphorus (TP) as well as microbial C, N and P (MBC, MBN andMBP respectively) concentrations in soils were collected through a literature review, andstudied to analyze the differences between agricultural land-use and natural land, and betweendifferent climate zones. The minimum concentrations of SOC, TN, MBC, MBN and MBP werefound in the agricultural soils and the maximum concentrations in natural soils. The minimumTP concentration was the same for the two land types but the maximum concentration wasfound in agricultural soils. The mean concentrations of MBC, MBN, MBP, SOC and TN weresignificantly lower in the agricultural land than in the natural land.The highest concentrations of soil and microbial C, N and P were found in the tropical wetclimate, in the highlands, in the midlatitude climate with high temperature variations, and in themarine west coast climate. The results show that: 1. rainfall and mild to warm temperaturescould increase nutrient concentrations; 2. northern latitudes and highlands have high stocks ofnutrients, and 3: Humid subtropical climates are probably more exploited to humans due toagricultural productivity which decreases nutrient concentrations.The results clearly show the loss of nutrients following cultivation, and the importance ofresearch of nutrient status in soils; for global soil and water quality issues, for a sustainableagricultural production and for ecosystems.