Cultivation techniques and nutrient management strategies to improve productivity of rain-fed maize in semi-arid regions

A field study was conducted during 2015-16 in a semi-arid area of the Loess Plateau China to clarify the interactive effects of cultivation techniques with different N and P fertilization levels on the maize growth, yield, evapotranspiration, and water use efficiency. Two planting models were tested: conventional flat planting (M1), and ridge furrow (RF) rainfall harvesting planting model (M2); with four N:P fertilizer rates: 0:0 kg ha-1 (F0); 100:50 kg ha-1 (F1); 200:100 kg ha-1 (F2), and 300:150 kg ha-1 (F3). The RF system increased the soil water storage (SWS), where the SWS exhibited a decreasing trend as the fertilization rate increased under both cultivation models. At 120 days after planting (DAP) the mean, SWS at the depth of 0-200 cm under the M1F0, M1F3, M2F0 and M2F3 treatments was 376.5 mm, 345.7 mm, 350.6 mm and 325.4 mm. The mean WUE over 2 years increased significantly (P <  0.05) with M2F3, M2F2, M1F3, M1F2, M2F1, and M1F1 by 53%, 37.7%, 34.7%, 31.9%, 21.6%, and 19.0% compared with M1F0 and M2F0 treatments. Maize responded positively to fertilizer, and F2 was the economical fertilizer input rate, where the leaf area, dry matter accumulation and grain yield increased significantly with increasing fertilization rate up to the economically optimal rate (F2). Beyond the optimal rate, these quantities increased slightly as did the yields and economic returns. Agronomic efficiency steadily decreased with fertilization rate beyond the F1 level. The economic benefit was 54% greater under M2F2 treatment, which also obtained significantly higher grain yield, WUE and agronomic efficiency than that of M2F0 treatment. Thus, we recommend the M2F2 planting model for high productivity and efficient maize production in semi-arid regions.