平原农区幼龄杨树间作农作物的产量表现

通过1~2年与3~4年树龄杨树间作冬小麦和夏玉米,探讨了杨树对农作物产量及产量形成因子的影响。结果表明,1~2年树龄杨树间作冬小麦其产量有所增加,与夏玉米间作使其产量降低31.3%~33.7%。3~4年树龄杨树间作冬小麦的产量降低了36.9%~42.5%,间作夏玉米的产量降低了80.8%~87.4%,且距树越近产量越低。产量形成因子分析表明,杨树对冬小麦产量的影响主要为穗数。因此保证冬小麦分蘖期的肥水管理,在群体建立的基础上保证营养器官建成期所需的各种资源,为正常的穗粒数形成及粒重的充实奠定基础。对夏玉米的影响,随着杨树的生长,表现不一样,由穗粒数逐渐转变为穗数。复合系统建立初期应保证玉米拔节期到吐丝期所需资源,确保较多的穗粒数形成,而杨树生长2~3年后必须对杨树进行合理的管理,保证穗数的建立,减小夏玉米产量的降低。针对农林复合系统的复杂性,今后应综合考虑杨树和农作物光、热、水、肥等生物学特性,对其进行合理管理,尽可能做到杨树与作物的和谐共生。

Yield performance of winter wheat and summer maize intercropped with young poplar

A filed experiment of intercropping winter wheat and summer maize with young poplars was conducted to study the effects of poplar on crop yield and yield-forming factors.The results showed that compared with monoculture,intercropping with 1-2 years old poplar somewhat increased the wheat yield but decreased the maize yield by 31.3%-33.7%,while intercropping with 3-4 years old poplar decreased the wheat and maize yield by 36.9%-42.5% and 80.8%-87.4%,respectively.Among the yield-forming factors of winter wheat,ear number was the main one affected by poplar,and thus,more attention should be paid to the water and fertilizer management at the tillering stage of wheat.For summer maize,the main affected yield-forming factor was from grain number to ear number with the growth of poplar,and thereby,it was necessary to ensure the resources supply at the elongation-silking stage of maize,and to strengthen the management of poplar after its 2-3 years growth.It was suggested that in the practice of agro-forestry, an integral consideration must be made on the biological characteristics and reasonable management of tree species and crops.