Soil available phosphorus (SAP) and potassium (SAK) are indispensable for crops, and their stocks are important for food production needed for a growing global population. This study analysed 991 soil profiles across a large part of Romania covering forestland, grassland and cropland in almost all ecological regions. This study investigated SAP and SAK stocks for different soil depths and characterized their magnitude and variability within land uses under different environmental ecosystems, soil classes and soil types, for a better soil and land management under a temperate-continental climate. Cropland soils present the highest SAP and SAK stocks. Chernozems, Phaeozems and Vertosols possess the highest SAP and SAK stocks in Romania, representing the largest country's pool. Both SAP stocks and SAK stocks are significantly correlated with basic environmental properties, existing direct correlations between SAP, SAK, soil organic carbon (SOC) and total nitrogen (TN) stocks. For all land uses, SAP and SAK stocks correlated significantly and directly with each other, as well as with annual temperature, clay content, pH and sum of base cations, and inversely with altitude, slope and annual precipitation. The best predictive values using multiple regression models and basic environmental driving factors were found for forestland stocks of SAP and SAK, followed by grassland stocks, while the lowest prediction occurred for cropland stocks, probably due to the long-term additional nutrient input performed by farmers in cropland that changed the natural conditions otherwise present in grassland, and especially in forestland. Based on these results some management measures are discussed.

This paper examines ethnic differences in fuelwood consumption in rural households, using an original survey dataset from two western Chinese provinces with large ethnic minority populations. We use a Heckman two-stage selection model to explain the quantity of fuelwood consumed conditional on a decision to use fuelwood. We find that ethnic minority families are more likely than majority Han Chinese families to use fuelwood. We also find that a household's off-farm income has a stronger negative effect on the quantity of fuelwood consumed for the ethnic minority families than for the Han Chinese families. In addition, families owning a larger area of forestland are more likely to use fuelwood. Yet the quantity of fuelwood consumed, especially in ethnic minority families, does not increase with owned forestland. Finally, we find that coal, rather than electricity, is a substitute for fuelwood for residential cooking and heating.