Appropriate Water-Nitrogen Regulation Mode to Improve Productivity of Mixed-Sowing Grassland of Bromus inermis and Alfalfa

Abstract

Scientific selection of appropriate herbage planting management mode is an important guarantee to promote artificial grassland development and grassland productivity. In this study, three-year-old alfalfa (Medicago sativa L.) and bromus inermis were applied to analyze the effects of planting patterns (bromus inermis and alfalfa mixed-sowing D1, bromus inermis mono-sowing D2), nitrogen application (pure nitrogen) level (N1: 60 kg·ha−1, N2: 120 kg·ha−1), and water regulation (upper and lower limits of irrigation are calculated as a percentage of field capacity θf, W1: slight water deficit 65~85% θf, W2: moderate water deficit 55~85% θf, W3: serious water deficit 45~85% θf) on herbage growth and water-nitrogen use efficiency. This research applied the principal component analysis, the TOPSIS model, and the combination evaluation to evaluate each treatment. Results demonstrated that (1) the plant height, leaf area index, and yield of mixed-sowing herbage were 81.63%, 119.52%, and 111.51%, higher than the mono-sowing herbage. Increasing the amount of irrigation and nitrogen application could enhance herbage yield. The herbage yield with the W1N2 treatment was the highest. In this treatment, the mixed-sowing herbage yield was 26,050.73 kg·ha−1, and the mono-sowing herbage yield was 12,186.10 kg·ha−1. (2) The crude protein content of mixed-sowing herbage increased by 41.44%, higher than mono-sowing herbage, and the relative feeding value decreased by 16.34%. Increasing irrigation and nitrogen application could improve the quality of herbage. Meanwhile, the quality of herbage treated with W1N2 was the best. (3) The water use efficiency (WUE), irrigation water use efficiency (IWUE), partial factor productivity of nitrogen (PFPN), and crude protein water use efficiency (CPWUE) of mixed-sowing herbage were significantly higher than mono-sowing herbage. The PFPN and the CPWUE of herbage improved with increasing irrigation amount. Meanwhile, the WUE, the IWUE, and the CPWUE of herbage also improved with increasing nitrogen application amount. The results showed that mixed-sowing of alfalfa and bromus inermis with slight water deficit (upper and lower limit of irrigation was 65~85% θf) and nitrogen application (120 kg·ha−1) could have the best comprehensive production effect. At the same time, it was a planting and management mode of high yield, high quality, and high efficiency of artificial herbage in the oasis-desert interlacing area of Hexi, Gansu Province, China, and areas with similar climates.

Effects of nitrogen fertilization combined with subsurface irrigation on alfalfa yield, water and nitrogen use efficiency, quality, and economic benefits

“…In addition, it was found that PEPN was significantly affected by irrigation and N application, and fertilization had a greater effect on NUE than irrigation. This further suggests that optimizing water and N supply can improve alfalfa N use efficiency, thereby increasing productivity ( Kang et al., 2023 ).…”

Effects of the fermentation quality and microbial community of waxy maize mixed with fodder soybean silage

“…The dried samples were pulverized and passed through a 40-mesh screen for subsequent measurements. The crude protein (CP) content was determined using the Kjeldahl method (Kang et al, 2023). The crude fat (EE) content was determined using the Soxhlet extraction method (Sosnowski and Truba, 2023).…”

“…The crude ash (Ash) content was determined using the high-temperature burning method in a muffle furnace (Sosnowski and Truba, 2023). The relative feeding value (RFV) was calculated according to the method described by Kang et al (2023). The samples (20 g) were mixed and homogenized with sterile water (180 mL) and filtered through four layers of gauze for the determination of fermentation indicators.…”