PERMFILE109663 - Laserfiche WebLink

Home Browse Search

Page 9 December 7, 1987 M-S7-171 Adequacy Responses Steven Renner So, it appears that the use of the water in this operation would probably not be proper at this time. Of course, the water will still be used for stock watering so long as grazing continues on the land east of the operation and west of the interstate. Water for this operation will therefore be obtained by agreement from other parties, unless the spring is investigated more thoroughly in the future and it is found to be of proper use rights. In that case, it would probably be used as a contribution to the water budget for the operation. QUESTION 4: The staff has found that a crimped mulch application (such as air~lried straw) not only resists wind erosion, but greatly enhances the organic matter content of replaced topsoil and helps to protect seed from foraging wildlife. The Division suggests that the operator evaluate crimping two tons of air-dried straw per acre subsequent to seed application. RESPONSE: We are familiar with the merits of mulches in revegetation. However, those merits do not come without some significant problems. The use of a mulch to retard wind erosion can work well, but is probably no more effective than ridging at right angles to the strongest expected winds. We feel that the use of mulch in protecting seed from foraging wildlife is subject to question. Straw mulch might have this effect, but other mulches which do not exhibit the biological problems of straw certainly would attract wildlife as a food source. It is a matter of straw vs. hay. The greatest problem with mulch is the aspect of adding organic matter to the soil. Although straw certainly would add significant amounts of organic matter, straw is primarily a high carbon source. If the soil, as is generally true of acid and semi-arid soils, already exhibits a somewhat unfavorable carbon/nitrogen ratio, then the addition of more high carbon material simply makes the soil less capable of producing desirable growths. The carbon/nitrogen ratio, which should ideally be at about 20:1, is very important in producing adequate fertility. When the ratio exceeds about 50:1, which can very easily occur when carbon based mulches are used, the nitrogen fertility of the soil can be severely affected and production will decrease markedly. In order to counteract this problem, additional amounts of nitrogen fertilizer can be added to help in the decomposition of the carbon material. Unfortunately, such additions of nitrogen fertilizer do not always work well in acid lands where decomposition is exceedingly slow in the first place. Often the nitrogen is lost to the atmosphere before significant decomposition can occur and nitrogen deficiency resulting from an unfavorable carbon/nitrogen ratio can still reduce production. This is one of the advantages of hydromulch - the mulch particles are smaller and decompose more rapidly. Unfortunately in acid lands hydromulch can actually make a revegetation project fail through its wicking action which draws rater out of the soil; water that may already be in a severe deficit.