Influence of Tied-Ridge with Maize Straw Biochar on Alfalfa Fodder Yield, Nutritional Quality, and Production Economics

Alfalfa (Medicagosativa L.) is commonly fed to a wide range of livestock as hay or silage. However, the impact of management practices on alfalfa productivity is under-studied. Thus, the objective of this study was to investigate whether ridge-furrow rainwater harvesting technology with biochar compared to flat planting affects alfalfa fodder yield and nutritional quality in China’s Loess Plateau. A study was carried out in a split-plot design. The treatments were maize straw biochar applied at 30 t ha⁻¹ vs. no-biochar-amended soil (control) and rainwater harvesting methods namely tied-ridging (TR), open-ridging (OR), and flat planting (control). Application of biochar to TR significantly (p < 0.05) increased alfalfa fodder yield compared to the OR treatment. The CP concentration of alfalfa fodder for the OR with biochar addition increased by 37.62% compared with OR with no-biochar application. The ADF of alfalfa cultivated on the biochar-amended soil increased by 10.74% compared with the no-biochar application. Regardless of biochar application, NDF for the alfalfa grown on OR increased by 6.04% compared with the FP. Relative feed value and net economic benefit of alfalfa fodder tended to increase for the TR with biochar application than the no-biochar treatment during the two growing seasons. Evidence from the 2-year experiment suggested that integrating maize straw biochar and ridge-furrow rainwater harvesting significantly increased alfalfa fodder yield, CP, ADF, and NDF. Based on our findings, we recommend the use of ridge-furrow rainwater harvesting, together with the amendment of maize straw biochar, to help increase alfalfa fodder yield in semi-arid areas.