A Study On Complementary Forage System In Subtropical Mid-mountain Areas

Most of southern China areas are subtropics, which are hot in summer and cold in winter, and it is hard for warm-season grasses overwintering and cool-season grasses surviving in summer. The development of animal husbandry is seriously confined because of seasonal lack of forages.Complementary forage system can overcome these deficiencies by oversowing cool-season grasses or legumes into warm-season perennial grasses in autumn to achieve a year-round growing season.Oversowing can also add nitrogen in the case of legumes, provide weed control and avoid erosion.The trial is composed of two sections,warm-season perennial grass—annual ryegrass systems and warm-season perennial grass—cool-season perennial grass+white clover systems. Warm-season perennial grasses—annual ryegrass system contains four treatments: Paspalum wettsteinii—Lolium multifolorum system,Setaria sphacelata—Lolium multifolorum system,Pennisetum clandestinum—Lolium multifolorum system and Brachiaria—Lolium multifolorum system.Perennial complementary forage system contains three warm-season grasses(Paspalum wettsteinii, Setaria sphacelata and Brachiaria)and three cool-season forage treatment(Lolium perenne+Trifolium repens, Festuca arundinacea+Trifolium repens and Dactylis glomerata+Trifolium repens)(1)Adaptability and performance of four warm-season forages in northern subtropics were studied during 2009 from May to November. The results showed that the hay yields of Brachiaria and Setaria sphacelata were significantly higher than Paspalum wettsteinii and Pennisetum clandestinum (P<0.05);most of the dry matter was cumulated from July to October. Quality of the forages in vegetative stage was better than it in flowering stage.(2)The study about warm-season perennial grass—annual ryegrass systems showed that oversowing annual ryegrass increased forage production of perennial warm-season pasture significantly (P<0.05); the yield of Brachiaria—Lolium multifolorum was the highest(26.34 t/ha) Pennisetum clandestinum—Lolium multifolorum had the highest crude protein production(2.90t/ha).Lolium multifolorum was dominant species in winter and spring, and it accounted for 40% of the forage production.(3)There were nine treatments of warm-season perennial grass—cool-season perennial grass+white clover systems, and oversowing increased forage production of all.The added production of Setaria sphacelata and Brachiaria pastures was more than that of Paspalum wettsteinii.The cutting times of the treatments oversowing Lolium perenne+Trifoium repens (10 times) were more than that of oversowing Festuca arundinacea+Trifolium repens and Dactylis glomerata+Trifolium repens (8 times).Trifolium repens accounted for more percentage in the treatments oversowing Festuca arundinacea+Trifolium repens of the same warm-season pasture.(4) The yield of these 13 forage production systems established in this trial is higher than the traditional annual ryegrass+forage maize system, except Pennisetum clandestinum—Lolium multifolorum system. Brachiaria—Lolium perenne+Trifolium repens had the highest yield (30.76 t/ha DM), and it was 1.57 times of traditional annual ryegrass+forage maize system.(5) Crud protein yield of these systems established in this trial was higher than annual ryegrass+forage maize system and annual ryegrass+Paspalum distichum system. Setaria sphacelata—Festuca arundinacea+Trifolium repens system had the highest CP yield (3.82t/ha), and it was 1.59 times of traditional annual ryegrass+forage maize system.