Tang C, Unkovich M J, Bowden J W
1 Centre for Legumes in Mediterranean Agriculture, The University of Western Australia, Nedlands, WA 6907, Australia.
New Phytol. 1999 Sep;143(3):513-521. doi: 10.1046/j.1469-8137.1999.00475.x.
Leaching of nitrate through soil profiles is a major cause of soil acidification. Legume species differ in their ability to take up nitrate (NO ) and in the degree to which soil NO impairs legume nodulation and N fixation. This pot experiment examined species variation in N fixation and acid production in grain legumes grown for 6 wk on a sandy soil with Ca(NO ) added at 0-56.7 mg N kg soil. The eight legumes studied were Lupinus angustifolius ('Gungurru'), Lupinus albus ('Kiev mutant'), Lupinus luteus ('Teo'), Cicer arietinum (Selection T1587), Pisum sativum ('Dundale' and 'Wirrega'), Vicia faba ('Fiord') and Lathyrus sativus (Selection 453). While number of nodules was not significantly affected by treatment with NO , increasing supply of NO decreased nodule mass, with P. sativum'Wirrega' being most sensitive and C. arientinum and V. faba least sensitive. The concentrations of nitrogen in plants generally decreased as the supply of NO increased. Increasing supply of NO decreased the percentage of N fixation, most significantly in L. sativus and least in L. albus. In the absence of added NO , the amounts of H produced per unit biomass (specific acid production) differed by as much as 2.2-fold among the species, with C. arientinum generating most H , followed by L. angustifolius, L. luteus, L. albus, V. faba, L. sativus, P. sativum'Dundale' and P. sativum'Wirrega'. This species variation was even greater at higher NO supply. In the presence of NO at up to 14.2 mg N kg , acid production by these legumes correlated well with uptake of excess cations but not with the concentration of nitrogen in plants. For all species, release of H declined with increasing supply of NO , decreasing most in L. sativus and least in C. arientinum. The results suggest that there might be scope for selecting grain legume species in order to minimize soil acidification by decreasing leaching of NO .
硝酸盐通过土壤剖面淋溶是土壤酸化的主要原因。豆科植物在吸收硝酸盐（NO ）的能力以及土壤中的NO 对豆科植物结瘤和固氮的损害程度方面存在差异。本盆栽试验研究了在添加了0 - 56.7 mg N/kg土壤的Ca(NO )的沙质土壤上种植6周的籽粒豆科植物在固氮和产酸方面的物种差异。所研究的8种豆科植物分别是窄叶羽扇豆（‘Gungurru’）、白羽扇豆（‘Kiev突变体’）、黄羽扇豆（‘Teo’）、鹰嘴豆（选择系T1587）、豌豆（‘Dundale’和‘Wirrega’）、蚕豆（‘Fiord’）和草豌豆（选择系453）。虽然根瘤数量不受NO 处理的显著影响，但随着NO 供应增加，根瘤质量下降，其中豌豆‘Wirrega’最敏感，鹰嘴豆和蚕豆最不敏感。植物中的氮浓度一般随着NO 供应增加而降低。随着NO 供应增加，固氮百分比下降，在草豌豆中下降最显著，在白羽扇豆中下降最少。在不添加NO 的情况下，单位生物量产生的H量（比产酸量）在不同物种间相差高达2.2倍，其中鹰嘴豆产生的H最多，其次是窄叶羽扇豆、黄羽扇豆、白羽扇豆、蚕豆、草豌豆、豌豆‘Dundale’和豌豆‘Wirrega’。在较高的NO 供应水平下，这种物种差异更大。在高达14.2 mg N/kg的NO 存在下，这些豆科植物的产酸与过量阳离子的吸收密切相关，但与植物中的氮浓度无关。对于所有物种，H的释放随着NO 供应增加而下降，在草豌豆中下降最多，在鹰嘴豆中下降最少。结果表明，有可能通过选择籽粒豆科植物物种来减少NO 的淋溶，从而将土壤酸化降至最低。
