苜蓿与禾本科牧草混作对牧草器官间物质分配和产量的影响

Effect of different cropping patterns on forage organs matter distribution and yield in saline-alkali soil

【目的】研究盐渍化草场的苜蓿和禾本科牧草混作对牧草各器官间物质分配,全碳、全氮含量及产量的影响,筛选出适合盐渍化土壤的苜蓿种植方式。【方法】以苜蓿品种中草3号、草原3号和禾本科牧草老芒麦、无芒雀麦为试验材料,设4种牧草单作及2种苜蓿分别与老芒麦和无芒雀麦混作处理,测定不同处理、不同生育期牧草的株高、鲜质量、干质量、全氮含量、全碳含量及产量等指标。【结果】苜蓿与老芒麦、无芒雀麦混作有利于提高其株高。苜蓿生长初期以茎部器官鲜、干质量积累为主,中期以茎部和叶部积累为主,开花期后逐渐向花积累。老芒麦和无芒雀麦各器官中的全碳总含量小于中草3号和草原3号,全氮含量低于二者;混作处理提高了老芒麦和无芒雀麦的全氮含量。中草3号与老芒麦混作处理显著提高了牧草产量(P<0.05),2次刈割时干草产量分别较中草3号单作处理提高了15.63%和21.95%,较老芒麦单作处理提高了1.23%和8.48%,且中草3号单作处理的牧草产量高于草原3号。叶、茎、花干质量和花全碳含量均与干草产量呈极显著正相关(P<0.01)。【结论】中草3号与老芒麦混作处理适合在盐渍化偏重地区推广种植。

[Objective] This paper studied the effect of mixed cropping on forage organs matter distri- bution, carbon content, nitrogen content and yield changes in alfalfa saline pasture to select proper planting patterns on saline land. [Method] Artificial grasslands with legume-graminaceous crop mixed cropping pat- terns using alfalfa varieties Zhongcao No. 3,Caoyuan No. 3,Elymus sibiricus and Bromus inermis were se- lected and monoculture and mixed cropping patterns were established. Plant height, fresh weight, dry weight,nitrogen content, and carbon content were measured. [Result] Mixed cropping with alfalfas and Elymus sibiricus and Bromus inermis improved plant height. The stem organ matter accumulated mostly at early growth period of alfalfa, leaf and stem organ matter accumulation increased at middle stage, and the matter transferred to flower gradually after flowering period. Total carbon and nitrogen contents of differ- ent organs of Elymus sibiricus and Bromus inermis were lower than that of Zhongcao No. 3 and CaoyuanNo. 3. Mixed cropping treatments improved the total nitrogen contents of Elymus sibiricus and Bromus in- ermis. Zhongcao No. 3 and Elymus sibiricus mixed cropping treatment improved forage yield significantly （P〈0.05）. In the two cutting production processes,dry grass productions of Zhongcao No. 3 in Zhongcao No. 3 and Elymus sibiricus mixed cropping were 15.63% and 21.95% higher than those of monoculture Zhongcao No. 3,and 1.23% and 8.48% higher than those of monoculture Elymus sibiricus, respectively. The yield of monoculture Zhongcao No. 3 was higher than that of Caoyuan No. 3. Dry weights of leaf, stem and flower, total carbon content of flower, and dry grass yield all had very significantly positive correlation （P〈0.01）. [Conclusion] Zhongcao No. 3 and Elymus sibiricus mixed cropping treatment is suitable for planting on heavy saline-alkali areas.