Multi-Cutting Improves Forage Yield and Nutritional Value and Maintains the Soil Nutrient Balance in a Rainfed Agroecosystem.

Tengfei Li,Yu Zhang,Yingxin Wang,Hua Wang,Yunxiang Cheng,Fujiang Hou,Luxi Peng

doi:10.3389/fpls.2022.825117

Abstract

Increasing forage yield and nutritional quality under the premise of maintaining relatively stable land area and soil nutrient content is a necessary condition for the sustainable development of grassland animal husbandry. Different cutting models [simulated grazing (SG), hay harvesting (H)] of oat (Avena sativa), common vetch (Vicia sativa) and their mixture (Avena sativa + Vicia sativa) were studied on the Loess Plateau. The results show that (1) SG could increase forage yield, crude protein, and crude fat content and decrease crude ash content. In 2014, the yield of Avena sativa per hectare was 3,578.11 kg higher than that of H; (2) the model analysis for predicting nutritional components showed that the Crude protein (CP) and EE contents of forages in each variety (combination) showed a linear downward trend with increasing forage yield. Redundancy analysis showed that precipitation, especially in the growing season, was positively correlated with grass yield and CP content; and (3) there were significant differences in soil organic carbon, total nitrogen, NO3−-N, and NH4+-N contents for the different forage varieties (combinations) under different use modes; the values first decreased, then increased, and finally decreased. According to the comprehensive evaluation value calculated by Technique for Order Preference by Similarity to an Ideal Solution, mixed sowing was better than monoculture, and SG obtained better results than H. Overall, mixed sowing under SG can improve forage yield and nutritional quality. At the same time, precipitation regulation is the key factor affecting the production performance of rainfed cultivated grassland on the Loess Plateau.

Highlights

Natural grassland accounts for about 40% of China’s terrestrial area and is the basis for the grazing livestock industry in the country (Kang et al, 2007)
The analysis of yield results of forage varieties between different years showed that the yields of Vicia sativa and Avena sativa in 2014 were significantly higher than those in 2015 and 2016, and the yields of Vicia sativa + Avena sativa under two different cutting modes were higher than those in 2015 and 2016, respectively
We found that, compared with hay harvesting, simulated grazing can improve the yield of high-quality forage and has a greater advantage for the forage value of various combinations

Summary

Introduction

Natural grassland accounts for about 40% of China’s terrestrial area and is the basis for the grazing livestock industry in the country (Kang et al, 2007). Cultivated grassland is utilized efficiently and rationally by grazing livestock rather than through the harvest of seeds and hay. Different use modes, intensities, and periods will affect the yield and quality of forage, thereby affecting the growth and development of herbivorous livestock and the production of livestock products. Selective feeding of animals (grazing preference) can change the competitiveness of forage species. Animal feeding directly affects the growth and reproduction of forages, and the biomass of forage plants with strong grazing tolerance (supercompensation ability) increases after grazing. By using compensatory and balanced growth characteristics of plants, mowing cultivated grassland can promote forage growth, affect forage yield, and change the distribution of forage nutritional quality and deposition (Iraj and Sharrow, 1990)

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Discussion

Conclusion