Crop yields and soil organic carbon dynamics in a long-term fertilization experiment in an extremely arid region of northern Xinjiang, China

Abstract

A long-term fertilization experiment was set up in northern Xinjiang, China to evaluate the dynamics of crop production and soil organic carbon (SOC) from 1990 to 2012 with seven fertilization treatments. The seven treatments included an unfertilized control (CK) and six different combinations of phosphorus (P), potassium (K), nitrogen (N), straw (S) and animal manure (M). The balanced fertilization treatments had significantly (P<0.05) higher average yields than the unbalanced ones. The treatment with 2/3 N from potassium sulfate (NPK) and 1/3 N from farmyard manure (NPKM) had a higher average yield than the other treatments. The average yields (over the 23 years) in the treatments of NPK, and urea, calcium superphosphate (NP) did not differ significantly (P>0.05) but were higher than that in the treatment with urea and potassium sulfate (NK; P<0.05). The results also show that the highest increases in SOC (P<0.05) occurred in NPKM with a potential increase of 1.2 t C/(hm 2 •a). The increase in SOC was only 0.31, 0.30 and 0.12 t C/(hm 2 •a) for NPKS (9/10 N from NPK and 1/10 N from straw), NPK and NP, respectively; and the SOC in the NP, NK and CK treatments were approaching equilibrium and so did not rise or fall significantly over the 23-year experiment. A complete NPK plus manure fertilization program is recommended for this extremely arid region to maximize both yields and carbon sequestration.

Long‐term fertilization effects on crop yield and desalinized soil properties

“…We found that after the 20‐yr long‐term fertilization, there is significant difference in the crop yields and soil properties in desalinized soils. The long‐term application of OF significantly increased crop yields, similar to that reported in other areas (Huang, Zhang, Yu, & Huang, 2010; Lyu et al., 2017). This might be due to the long‐term addition of manure to soil, which released nutrients (macro‐ and micronutrients) gradually, increased soil organic matter contents, and improved soil physical and chemical properties (Choudhary et al., 2018; Sanz‐Cobena et al., 2017).…”

“…From our long‐term fertilizer application experiment, we found that OF had the most benefit to SOC content. This indicated that application of manure can improve agricultural root biomass and exudates, as well as organic C generation, and thus increase SOC capacity (Liu et al., 2015; Lyu et al., 2017). Additionally, manure is also rich in organic matter that may improve soil structure, aeration, and soil fertility (Chen et al., 2015; Ge et al., 2018).…”

Assessment of soil quality for guided fertilization in 7 barley agro-ecological areas of China

“…Hence, K, Mg, Fe and Cu might be limiting factors for soil quality in this area. The pH, available K and DTPA-Cu levels in farmlands of North Xinjiang were similar to the result of Lyu et al [48]. NO 3 --N, DTPA-Fe and Clin this area showed lower levels compared with other areas in temperate regions, tropical regions or semiarid areas due to the particular background of the soil and climatic conditions (Figs 2E, 3F and 3H).…”