Improvement of new farmland soil in loess area under different fertilization treatments

The study was conducted in new farmland of hilly loess region of western Shanxi Province where soybean is planted. We compared and analyzed the effect of six different fertilization measures, i.e.,organic fertilizer only(M), organic fertilizer + inorganic fertilizer(M + NPK), bio鄄fertilizer only(B), bio鄄fertilizer + inorganic fertilizer(B + NPK), applied inorganic fertilizer(NPK) and controlcheck(CK),on raw soil physical properties and changes in soybean yield. The results showed that allfertilization measures could improve the physical properties of raw soil to some extent and increase thesoybean yield. Among them, B + NPK had the most significant effect in increasing maximum moisturecapacity and field moisture capacity, with the maximum moisture capacity 362郾80 g/ kg, 15郾23% higherthan CK and 1郾85% - 4郾46% higher than the other four measures; the field moisture capacity was 340郾20 g/ kg, which was 15郾54% higher than CK and 1郾45% - 3郾19% higher than the other fourmeasures. The effects of M + NPK were the most significant in reducing soil density, increasing soil porosity, improving soil mechanical composition, promoting the formation of water鄄stable aggregates, and heightening soil organic matter content, and the soybean yield under this measure was the highest in the five measures, up to 173郾55 g/ m2, having a 235郾95% increase compared with CK and a 18郾20%-125郾80% increase compared with the other four measures. Therefore, M + NPK was the optimum measure to improve raw soil physical properties and increase soybean yield in new farmland in the loess area of western Shanxi.