Welcome to Acta Prataculturae Sinica ! Today is Share:

Acta Prataculturae Sinica ›› 2025, Vol. 34 ›› Issue (4): 53-63.DOI: 10.11686/cyxb2024210

Previous Articles     Next Articles

Effect of nitrogen application on production performance and nitrogen fertilizer contribution of forage sorghum/lablab mixed cropping

Bin WANG1,2(), Jia-mei SHI3, Teng-fei WANG1,2, Yi-yin ZHANG1,2, Jiang-ping MA1,2, Jia-wang LI1,2, Xiao-bing WANG1,2, Jian-qiang DENG1,2(), Jian LAN1,2()   

  1. 1.College of Forestry and Grassland,Ningxia University,Yinchuan 750021,China
    2.Ningxia Grassland and Pasture Engineering Research Center,Yinchuan 750021,China
    3.Bureau of Agriculture and Rural Affairs,Pingluo County,Shizuishan 753000,China
  • Received:2024-06-04 Revised:2024-07-29 Online:2025-04-20 Published:2025-02-19
  • Contact: Jian-qiang DENG,Jian LAN

Abstract:

This research investigated the effect of nitrogen application on the forage yield and nutrient utilization of forage sorghum (Sorghum bicolor) variety “Hulk” and lablab (Dolichos lablab) variety “High Value” under different cropping patterns. A split-plot experiment was conducted at the Grass Science Teaching and Research Base of Ningxia University in 2021-2022, with two planting patterns (sole forage sorghum (SS), forage sorghum/lablab mixed cropping (SL) as main plot treatments, and four nitrogen (N) application rates (N0, 0 kg·ha-1; N90, 90 kg·ha-1; N180, 180 kg·ha-1; and N270, 270 kg·ha-1) as the sub-plot treatments, to measure the related indexes of yield, nutrient quality and nitrogen fertilizer utilization efficiency. It was found that forage sorghum/lablab mixed cropping combined with N fertilization promoted the growth of forage and improved the productivity of pastures. The dry matter yield and crude protein yield of forage were highest in the sorghum/lablab mixed cropping treatment with N application of 180 kg·ha-1, and were 28352 kg·ha-1 and 2481 kg·ha-1, respectively. These values were higher than corresponding values of sole forage sorghum by 14.8% and 25.9%. Mixed cropping combined with N fertilization improved the nutritional quality of forage. At the N application of 180 kg·ha-1 in the mixed cropping system, stalk sugar content and relative feeding value increased by 10.3% and 18.9%, respectively, compared with that of sole forage sorghum in the N0 treatment. N application also significantly increased N fertilizer response, which was highest at 270 kg·ha-1 for sole forage sorghum and at 180 kg·ha-1 for the mixed cropping treatment. In addition, both N fertilizer agronomic use efficiency and N partial factor productivity of the mixed cropping treatment patterns across N fertilizer application rates differed from those of the sole forage sorghum plots, and reached their maximum at a N application rate of 90 kg·ha-1. In conclusion, forage sorghum/lablab mixed cropping combined with nitrogen application at 180 kg·ha-1 pattern is a suitable planting pattern and nitrogen application level for increasing forage yield, improving forage nutritional quality and improving nitrogen fertilizer utilization efficiency in the arid region of Ningxia.

Key words: mixed cropping, nitrogen fertilizer, production performance, nutritional quality, nitrogen fertilizer utilization