The effect of water-soluble and total nitrogen and of drying on the rate of nitrification of some common Florida weeds
1937
Bedsole, M.R. Jr
A number of weeds common to Florida were analyzed for watersoluble and total nitrogen. Also, the rate of nitrification was determined on these crops in both the green and dry stage, using Norfolk fine sand for cultures. The results may be summarized as follows: Boerhaavia, coffeeweed, careless weed, and crab grass contain a comparatively high percentage of water-soluble and total nitrogen, and appear suitable for cover crop purposes where a rapidly nitrifying material is required. Wire grass, pepper grass, sandburr, Spanish needle, and ragweed are low in total and water-soluble nitrogen and slow to yield available nitrates. The water-soluble nitrogen content appears to be the most important factor involved in the nitrification of green and dried plants followed by total nitrogen and degree of hydration or moisture in the order named. The nitrification of plants containing above 1.7% nitrogen and 1.7% water-soluble nitrogen is only slightly affected by driving, while plants containing less than 0.5% water-soluble nitrogen show a decrease in nitrification upon drying, even where the total nitrogen content is above 1.7%. If the water-soluble nitrogen is 0.5% or above, favorable nitrate accumulation occurs, even though the total nitrogen is less than 1.7%. Plants containing above 1.7% total nitrogen but less than 0.33% water-soluble nitrogen have a slow accumulation of nitrate nitrogen in the soil.
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