玉米二比空栽培增产机制的研究

在高密度栽培条件下,改变玉米植株的田间排列方式,将清种改为二比空栽培并以清种为对照进行研究发现:二比空栽培由于疏密不等排列,使群体受光强度增大,尤其是中、下部叶片受光强度更优于清种,在空垄空间分布的中、下部叶片,其光合强度高,处于原垄内叶片光合强度虽低,但其平均光合强度远高于清种;二比空栽培的玉米,各时期叶面积指数均大于清种,尤其是中后期更明显,故有利于玉米灌浆;二比空栽培的玉米,根系和茎叶干重后期下降速度较慢,从而保证了后期的正常生长;二比空栽培根冠比小于清种;多点试验结果表明,二比空比清种增产11.2％～12.3％。

Yield--Increasing Mechanism in 2--0 Culture of Maize

On the high density culture condition of maize, 2-0culture was studied in comparison with uniform culture. It wasdiscovered that: because of the uneven sparse-dense arrangement, thelight-intensity increased in the population of 2-0 culture;particularly in the middle-lower part, the leaves got more light than thatof the uniform culture; the middle lower leaves distributed upon the inoccupied ridges had high photosynthetic and the average photosyntheticis higher than that of nuiform culture, although the leaves distributedupon the occupied ridges had lower photosynthetic intensity; the leaf-areaindex was higher in 2-0 culture than that in uniform culture in everystage, particularly the middle-later stage, hence beneficial to seed-filling; the dry-weight of root system and straw decreased slowerin the middle-later stage for 2-0 culture, which ensured normallatre stage growth; the root-crown ratio is smaller for 2-0 culture.It was proved. in multi-point experiment that the yield increased11.2%-12.3% in 2-0 culture than that in uniform culture.