红壤旱地玉米对间作大豆和花生边行效应影响的研究

Marginal effect of soybean and peanut intercropped with maize in upland red soils

为深入了解间作豆科作物的边行效应,研究了低施氮肥条件下(50 kg·hm-2)玉米对间作大豆和花生边行(叶绿素、叶面积指数、根干重、根瘤、农艺性状及产量)的影响。结果表明:无论在施氮肥和不施氮肥条件下间作大豆和花生边1行和边2行的叶绿素含量在不同生育时期均高于其单作,而边3行与单作相比变化不明显。间作同样可以增加大豆和花生不同生育时期边1行和边2行的叶面积指数,而对边3行无明显影响,且间作的效果小于该施氮水平。不施氮条件下,间作大豆边1行和边2行的单株根干重高于单作14.7%和2.8%,间作花生边1行和边2行高于单作16.5%和3.1%;施氮条件下,间作大豆边1行和边2行的单株根干重高于单作11.3%和1.3%,间作花生边1行和边2行高于单作13.5%和4.6%,而边3行与单作相比无明显变化,且该施氮肥的效果大于间作。间作同样可以增加大豆和花生边1行和边2行成熟期的单株根瘤数和根瘤重,而对边3行无明显影响,而该施氮水平对根瘤数和根瘤重具有一定的抑制作用。施氮肥和间作可以改善大豆和花生的农艺性状,以施氮肥条件下边1行优势最为明显。不施氮肥和施氮肥条件下间作大豆和花生边1行和边2行的单株经济产量和生物产量及行产量皆高于相应单作,并以边1行为最高,而边3行与单作相比变化不明显,且施氮肥在改善大豆和花生农艺性状提高产量方面的效果大于间作。因此本试验得出间作边行优势效应为边1行>边2行>边3行(单作),且施氮肥的效果大于间作边行效应。

To understand the marginal effect of leguminous crops in intercropping systems of maize, chlorophyll content, leaf area index, root dry weight, root nodule, agronomic traits and yield of border-row soybean and peanut were determined under low nitrogen （50 kg＇hm-2） fertilized soybean-maize and peanut-maize intercropping systems. The field experiment was carried out in the Upland Red Soil Experimental Station of Jiangxi Agricultural University for the period from Jul. 28, 2011 to Nov. 20, 2011. The results showed that the chlorophyll content of the first and second border-rows of intercropped soybean and peanut was higher than that of the mono-crop system at different growth stages with/without nitrogen fertilization. However, no obvious differences were noted in chlorophyll content between the third border-row of intercropped and mono-cropped soybean and peanut. While leaf area index of the first and second border-rows of intercropped soybean and peanut increased at different growth stages, no obvious change was noted in the third border-row, compared with the mono-cropped soybean and peanut. Also the effect of nitrogen fertilization under the mono-cropped was greater than that of the intereropping. Root dry weight of the first and second border-rows of intercropped soybean increased by 14.7% and 2.8% and those of intercropped peanut increased by 16.5% and 3.1%, respectively, compared with mono-cropped soybean and peanut under no nitrogen fertilization. Root dry weight of the first and second border-rows of intercropped soybean increased by 11.3% and 1.3% and those of intereropped peanut increased by 13.5% and 4.6%, respectively, compared with mono-cropped soybean and peanut under nitrogen fertilization. The third border-row of intercropped systems showed no obvious difference from mono-cropped. Nitrogen fertilization under mono-cropping showed greater effect than intercropping. Intercropping also increased per-plant root nodule number and weight of the first and second border-rows of intercropped soybean and peanut at maturity stage. It, however, showed no obvious effect on the third border-row and 50 kg.hm-2 nitrogen fertilization decreased root nodule number and weight. Nitrogen fertilization and intercropping improved agronomic traits of soybean and peanut, with the most significant marginal effect of the first border-row. The economic and biological yields per plant and yields per row of the first and second border-rows of intercropped soybean and peanut were higher than those of mono-cropping system with/without nitrogen fertilization. The first border-row presented the highest value, while the values of the third border-row were not obviously different from those of the mono-cropping system. Furthermore, the effects of nitrogen fertilization on agronomic traits and yield of soybean and peanut were greater than those of intercropping system. The study therefore showed that marginal advantages of intercropping was the first border-row 〉 the second border-row 〉 the third border-row mono-cropped system. The effect of nitrogen fertilization was greater than intercronDine.