Effect of thatch on water-soluble phosphorus of pasture soil fertilized with broiler litter

The presence of a thatch layer in established pastures could reduce the contact between broiler litter and soil, thus increasing the potential for surface runoff contamination with litter P. We conducted a laboratory study to evaluate the effect of a thatch layer on the dynamics of water-soluble P in undisturbed cores taken from a pasture. Cores with and without a thatch layer received a surface application of broiler litter (5 thm-2) and were incubated at 25 oC for 56 d. The result showed that on the soil surface the contents of water soluble-P (39 kghm-2) of the cores with the thatch layer was higher than that (20 kghm-2) of the cores without the thatch layer. Therefore on well-established pastures fertilized with broiler litter, the presence of a thatch layer might lead to high concentrations of water-soluble P on the soil surface.

对“Archer”大豆中瓜果腐霉引起的腐霉猝倒病抗性遗传基因图谱研究

腐霉猝倒和根腐病引起大豆出苗率严重减少,因此造成减产。有报道认为大豆品种Archer对由腐霉菌引起的苗期病害具有抗性,并描述了与之相关的Rps1k基因对疫霉菌具有抗逆性。为了描述大豆品种Archer抗腐霉猝倒病的遗传特性,并且确定该抗性是否与Rps1k基因相关,Archer和Hutcheson（感病亲本）进行杂交,F2：4体（子二代）产生。