Impact of Phosphorous Fertilization on Rape and Common Vetch Intercropped Fodder and Soil Phosphorus Dynamics in North China

Abstract

This study explores the effect of phosphorus (P) fractions, under P addition or not, based on a common vetch-rape model cropping system in alkaline soil. A two year field experiment was conducted at Tuzuo Banner modern agricultural Park in Inner Mongolia, China. Two phosphorus levels, including P0 (no fertilizer) and P45 (45 kg·ha−1 P), were performed in common vetch and rape either grown alone or intercropped. We analyzed the changes of the physicochemical properties and phosphorus fractions in the rhizosphere soil. Intercropping enhanced the common vetch and rape yield by 42.05% and 24.91%, on average, compared with corresponding sole cropping on an equivalent area basis. The average land equivalent ratio (LER) was 1.34. Intercropping had a significant AP concentration, of 65.32% and 33.99% at the P0 level, and 62.83% and 36.19% at the P45 level, respectively, compared to that of the sole common vetch and rape. With the application of P, intercropping improved the Resin-Pi and NaHCO3-Pi fraction (61.17%, 87.03% at the P0 level and 96.50%, 41.85% at the P45 level, compared to monocropped common vetch and rape in 2019). The changes in NaOH-Pi and NaOH-Po (except for NaOH-Pi in 2019) showed no significant difference between cropping systems. Intercropping significantly accumulated concentrations of HCl-P, while depleting Residual-P, in 2020. In conclusion, common vetch/rape with the addition of P polyculture stimulated rhizosphere soil P mobilization and had a yield advantage over sole cropping.

Spatial Distribution Characteristics of Soil C:N:P:K Eco-Stoichiometry of Farmland and Grassland in the Agro-Pastoral Ecotone in Inner Mongolia, China

“…The mean annual precipitation in area I is 150-380 mm, and the mean annual temperature is 3.7-7.6 • C. The topography of this area is dominated by plateaus, mountains, hills, and plains, with an elevation of 986-2280 m. Irrigation and silt soil, saline-alkali soil, chestnut soil, and meadow soil are the main soil types, and the main crops are wheat, sunflower, and corn [27]. The mean annual precipitation in area II is 150-500 mm, and the mean annual temperature is 0-6.7 • C. The topography of this area is dominated by plateaus, mountains, and hills, with an elevation of 1150-2350 m. Cinnamon soil and chestnut soil are the main soil types, and the main crops are wheat, rapeseed, sunflower, potato, and miscellaneous grain [28].…”