A new model of two-sown regime for oat forage production in an alpine region of northern China.

Demand for high forage production and quality has been increased markedly by development of animal husbandry in China. The lack of efficient planting regimes and key technologies greatly limits production of high-quality forage. Oat has become an important forage in animal husbandry in China due to its high nutritional value and forage yield as well as its great adaptation to harsh environment. To maximize oat forage production in an alpine region, we developed a new model of oat forage production known as two-sown regime, i.e., the first spring-sown and the second summer-sown, during a single growing season in an alpine region of Hulun Buir, Inner Mongolia Autonomous Region, China, using two early-matured oat species, Avena sativa (cv. Qinghai444, winner oat cultivar) and A. nuda (cv. Huazao2, spring oat cultivar). The key technologies and the underlying agronomic mechanisms were investigated across three experimental years of 2017-2019. The main results were as follows: (1) dry weight yield, crude protein yield, and relative feed value of forage in the two-sown regime were significantly increased by 53.6%, 48.9%, and 70.6% relative to traditional one-sown regime across the 3 years, respectively; (2) forage production was mainly achieved by an increase in plant height at the first spring-sown; and (3) forage yield resulted mainly from an increase in tiller density by increasing seeding rate under no-tillage treatment in the second summer-sown. The key technologies of the two-sown regime were the first spring-sown at the soil thawing depth 10-13 cm, followed by the second summer-sown with increasing seeding rate under no-tillage treatment. These findings highlight that the two-sown regime of oat forage can be widely used as an effective planting regime to maximize forage production in large alpine regions of northern China as well as in regions with similar climates.

Agronomic and economical characterizations of a two-harvest regime for oat forage in cold regions of Northern China.

The natural grasslands in northern China have been seriously degraded due mainly to overgrazing and climate change in recent decades, leading to shortage of forage supply to animal husbandry. To maximize forage production, we developed a two-harvest regime of oat forage by sowing in spring in an alpine region of Hulun Buir, northern China, using two oat early maturation species. The agronomic characteristics and forage quality of the two-harvest regime were evaluated across three constructive years from 2017 to 2019. Compared to the traditional one-harvest regime, the production, resource use efficiency, and economic benefits were compared and quantified for both oat species across the 3 years. Dry weight forage by the two-harvest regime was increased by 17.5-18.5%, while crude protein was increased by 25.1-30.0%. Growing days by the two-harvest regime was increased by 36.7% on average, nitrogen fertilizer use efficiency was enhanced by 25.1-30.0%, while water use efficiency was not significantly changed. The two-harvest regime also increased the net profit by 28.0%. Taken together, our results reveal that the two-harvest regime of forage production in the cold region of northern China is a promising practice with high forage yield, nutritional value, and nitrogen fertilizer use efficiency as well as economic profit.