Forage quality of triple maize crops with winter barley in Kyushu, Japan

Abstract

Background: Intensification of summer and winter forage cropping is an urgent requirement for reducing feeding costs for the beef and dairy cow industry in Kyushu, Japan. Based on the expectation of progression of global warming, the yield following quadruple cropping of triple maize crops with a winter barley crop was evaluated in a previous 2 years trial. Materials and Methods: Forage quality of the previous triple (spring, summer and autumn) maize with winter barley cropping was determined for 2 years in the region. Winter barley, sown in inter-rows in mid-November, was harvested in early to mid-March while spring maize, sown in early to mid-March, was harvested in early to mid-June, summer maize, sown from early to mid-June, was harvested in late August and autumn maize, sown from late August to early-September, was harvested in mid-November. Results: Yield of winter barley was around 900-930 g DM m-2, spring maize was 1440-1800 g DM m-2 with 41-59% ear DM and summer maize was 820-1170 g DM m-2 with 41-44% ear DM. However, the autumn maize yield varied greatly from 330-810 g DM m-2 with 33-56% ear DM due to typhoon and cool weather damage. In vitro DM digestibility (IVDMD) in maize ears was higher than 75% and in leaf blades was higher than 60%, while for barley leaf blade, it was higher than 80%; the values for stems were lower than leaf blades for all crops of both species. The IVDMD was negatively correlated with Neutral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF) concentration (r = -0.790 and -0.856, respectively) at the 1% probability level. By estimating Total Digestible Nutrient (TDN) concentration from ADF concentration based on regression equations, the TDN yield was 2750-2870 g DM m-2 year-1 over 2 years. Conclusion: Triple maize with winter barley cropping can produce 4090-4330 g DM m-2 year-1 with 66-67% TDN concentration in the region, which is recommended as a potential system for intensive ley farming.