This study was conducted with the aim of finding humic acid and crop residues effects on soil and wheat nitrogen at New Development Farm, University of Agriculture, Peshawar, Pakistan during winter 2009-2010. The expe...This study was conducted with the aim of finding humic acid and crop residues effects on soil and wheat nitrogen at New Development Farm, University of Agriculture, Peshawar, Pakistan during winter 2009-2010. The experiment was laid out in RCB design having four replications. Different levels (1, 1.5, 2 and 2.5 kg ha-1) of Humic acid were applied at sowing time. Mungbean (5 tons ha-1), wheat straw (10 tons ha-1) and mungbean (2.5 tons ha-1) + wheat straw (5 tons ha-1) were incorporated 30 days before sowing. Our results showed higher mineral and total nitrogen (7.32 and 0.43, respectively) mg kg-1 in soil and also higher nitrogen in stem, leaves and grains (2.3, 4.6 and 21.1, respectively) mg kg-1 at maturity in those plots in which 2.5 kg ha-1 of humic acid was applied. Higher mineral and total nitrogen (7.04 and 0.5, respectively) mg kg-1 in soil and also higher nitrogen in leaves (5.5) mg kg-1 at pre-anthesis, while at maturity stage in stem, leaves and grain (5.5, 2.1, 4.2 and 20.8) g kg-1 was recorded in those plots in which 5 tons ha-1 mung bean was incorporated. Our experimental results suggest the use of 5 tons ha-1 of mungbean residues with 2.5 kg ha-1 of humic acid to improve soil fertility availability of more nitrogen in wheat plants to increase the crop yield and grains quality.展开更多
Aims Leymus chinensis is an original dominant plant in the Songnen grassland,and it has great value for restoration of severely degraded land.However,seeds are dormant,and low germination percentage is a problem for r...Aims Leymus chinensis is an original dominant plant in the Songnen grassland,and it has great value for restoration of severely degraded land.However,seeds are dormant,and low germination percentage is a problem for restoring L.chinensis grassland.The mechanism of seed dormancy is not been well understood.The primary aims of the present study were to investigate the dormancy mechanism of L.chinensis seeds(caryopses)with reference to the role of embryo-covering layers,endogenous hormones and temperature.Methods Changes in concentration of the endogenous hormones GA3,indoleacetic acid(IAA),zeatin riboside(ZR)and abscisic acid(ABA)in L.chinensis seeds fromanthesis to maturity weremeasured by the enzymelinked immunosorbent assay method.Germination at different stages of maturity were tested at 16/28C,5/28C and 5/35C for intact seeds with glumes(control),intact seeds with glumes removed(nakedwhole seeds)and intact seeds with glumes and one-half of the endosperm removed(naked-half seeds).Important Findings Of the four endogenous hormones monitored,only the concentration of ZR differed significantly between the beginning and the end of seed development(increased);the GA3/ABA ratio also did not differ.Rank of germination percentage of control at the three temperature regimens was 5/28C>16/28C>5/35C.Germination percentage of the naked-half seeds reached 100%under the three temperature regimens.We concluded that dormancy of L.chinensis seeds is not mainly controlled by endogenous hormones.Germination temperature,mechanical resistance of glumes and inhibition of endosperm are the main factors controlling dormancy and germination of L.chinensis seeds.展开更多
文摘This study was conducted with the aim of finding humic acid and crop residues effects on soil and wheat nitrogen at New Development Farm, University of Agriculture, Peshawar, Pakistan during winter 2009-2010. The experiment was laid out in RCB design having four replications. Different levels (1, 1.5, 2 and 2.5 kg ha-1) of Humic acid were applied at sowing time. Mungbean (5 tons ha-1), wheat straw (10 tons ha-1) and mungbean (2.5 tons ha-1) + wheat straw (5 tons ha-1) were incorporated 30 days before sowing. Our results showed higher mineral and total nitrogen (7.32 and 0.43, respectively) mg kg-1 in soil and also higher nitrogen in stem, leaves and grains (2.3, 4.6 and 21.1, respectively) mg kg-1 at maturity in those plots in which 2.5 kg ha-1 of humic acid was applied. Higher mineral and total nitrogen (7.04 and 0.5, respectively) mg kg-1 in soil and also higher nitrogen in leaves (5.5) mg kg-1 at pre-anthesis, while at maturity stage in stem, leaves and grain (5.5, 2.1, 4.2 and 20.8) g kg-1 was recorded in those plots in which 5 tons ha-1 mung bean was incorporated. Our experimental results suggest the use of 5 tons ha-1 of mungbean residues with 2.5 kg ha-1 of humic acid to improve soil fertility availability of more nitrogen in wheat plants to increase the crop yield and grains quality.
基金Major State Basic Research Development Program of China(973 Program,2007CB106800)Action Plan of Chinese Academy of Sciences for West Development(KZCX2-XB2-13).
文摘Aims Leymus chinensis is an original dominant plant in the Songnen grassland,and it has great value for restoration of severely degraded land.However,seeds are dormant,and low germination percentage is a problem for restoring L.chinensis grassland.The mechanism of seed dormancy is not been well understood.The primary aims of the present study were to investigate the dormancy mechanism of L.chinensis seeds(caryopses)with reference to the role of embryo-covering layers,endogenous hormones and temperature.Methods Changes in concentration of the endogenous hormones GA3,indoleacetic acid(IAA),zeatin riboside(ZR)and abscisic acid(ABA)in L.chinensis seeds fromanthesis to maturity weremeasured by the enzymelinked immunosorbent assay method.Germination at different stages of maturity were tested at 16/28C,5/28C and 5/35C for intact seeds with glumes(control),intact seeds with glumes removed(nakedwhole seeds)and intact seeds with glumes and one-half of the endosperm removed(naked-half seeds).Important Findings Of the four endogenous hormones monitored,only the concentration of ZR differed significantly between the beginning and the end of seed development(increased);the GA3/ABA ratio also did not differ.Rank of germination percentage of control at the three temperature regimens was 5/28C>16/28C>5/35C.Germination percentage of the naked-half seeds reached 100%under the three temperature regimens.We concluded that dormancy of L.chinensis seeds is not mainly controlled by endogenous hormones.Germination temperature,mechanical resistance of glumes and inhibition of endosperm are the main factors controlling dormancy and germination of L.chinensis seeds.
