Effects of Plowing Depth and Organic Matteron Growing Dixie Grass (Sporobolus virginicus) on Northeastern Saline Soil :II. Increasing Numbers of Nitrifying Bacteria in Saline Soil

Abstract

We studied the effects of plowing depths and types of organic matters on soil properties, amount of nitrifying bacteria and yield of Dixie grass (Sporobolus virginicus (L.)). The experiment were conducted on salt affected paddy field in Khon Kaen province, We found that the grass plots with a 30 cm plowing depth had less exchangeable Na, less salinity, higher numbers of nitrifying bacteria, more of mineralized N and higher than the plots with 15 cm plowing depth. The grass plots received farm manure had least exchangeable Na, but higher in soil moisture, mineralized N, numbers of nitrifying bacteria and grass yield than the plots received compost or rice husk or non organic matters. These experiments showed that the grass plot received 30 cm plowing and farm manure yielded the highest dry matter and N concentration in Dixie grass.