Effects of different tillage modes on the status of nitrogen, phosphorus and potassium in Leizhou Peninsula latosol from basalt

Objective  To investigate the effects of different tillage modes on soil fertility properties of Leizhou Peninsula latosol from basalt.

Method  Taking the latosol from basalt in Leizhou Peninsula of China as test object, the variability of soil fertility properties were studied under eight tillage modes. The relationships among numerous fertility variables, integrated soil fertility, and key limiting factors were evaluated by principal component analysis (PCA).

Result  The effects of tillage modes on soil pH, organic matter, total nitrogen (N), available N, phosphorus (P), potassiumin (K), and slowly available K contents were significant (P<0.001). The results of PCA indicated that the differences in integrated soil fertility under eight tillage modes were significant (P<0.000 1), which was closely related to the field management. The integrated fertility of banana, vegetable, and paddy-paddy rotation fields were higher, in which that of banana field was the highest, followed by that of vegetable and paddy-paddy rotation fields. The soil organic matter, total N, available N, P, K, and slowly available K of banana field were 2.55, 2.44, 3.50, 2.30, 15.36 and 7.73 times respectively higher than those of cassava field. The limiting factor of fertility enhancement of banana field was the low soil pH, which was 0.89 lower than cassava field. The low organic matter and available P contents were limiting factors of fertility enhancement of banana, and paddy-paddy rotation fields, respectively. The paddy-sweet potato rotation, peanut-paddy rotation, and peanut-soybean rotation fields showed medium integrated fertility, while that of cassava and sweet potato fields were relatively low. The deficiencies of organic matter and N were the main limiting factors of their low integrated soil fertility.

Conclusion  Increasing application of organic fertilizer, reasonable combination of organic and inorganic fertilizers, and regulation of soil pH are key factors to further improve the integrated soil fertility of cultivation land.