| 'What if'
multiple land use could really work? By
HOWARD GRYDER It all began, as many discussions do, around the coffee table in the break room with a "what if" question. If, through fertilization, control of underbrush competition, proper thinning at the recommended age and proper size, we could produce sawlogs two or more years sooner than the time presently being used to estimate sawlog harvest from planting to cutting - approximately 25 years at the time. "What if" by using available broiler litter from the several hundred broiler houses located in the parishes of Union, Lincoln, Bienville, Jackson, and west Ouachita, and by using ruminant (plant-eating) animals to graze the competitive vegetative growth underneath the pine canopy, could the goal be reached? What we knew at the time, 1990, from work being done by Dr. Don Robinson from the LSU Baton Rouge campus in out-field agronomy work with graduate students, was that extensive soil sampling in Union Parish had revealed that continual application of broiler litter on the same acreage over time accounted for phosphorus buildup in the hill soils of the parish. Soil sampling to 36 inches indicated that both the topsoil and subsoil would hold several hundreds parts per million (ppm) of phosphorous. Earlier tests by commercial timber companies on fertilization of pine tree stands showed that the pine seedlings and young pine timber responded favorably to fertilizer, especially those with a higher phosphorous content. Next, we knew from having several hundred samples of broiler litter analyzed that it contained a considerable amount of nitrogen (N), phosphorous (P), and potassium (K) in a 2:2:1 ratio in most samples. We are also aware of the volatile nature of nitrogen, allowing it to evaporate into the air reducing its ability to provide plant nutrients, and the immobile nature of P and K, meaning they pretty much remain where they are in the soil, being absorbed less readily by plants. Finally, we were aware of new guidelines for the application of broiler litter that were being put in place in Arkansas, based on the degree of slope and soil type. Discussion was well toward final recommendations for per-acre per-year amounts in Louisiana. If some of the cut-over lands and thinned timber stands could be used for sites to apply the many tons of broiler litter each year in the area, perhaps the poultry producers would find a new and different use for their by-product without having to ship it out of the area, which is an added cost to someone. After many discussions and the passing of time, Steve Hotard, area extension forester, and Dr. Ron Robbins, resident director of the Calhoun Research Station, plus Dr.Terry Clason, the research forester from the Hill Farm Research Station in Homer, planned and started 70 acres of the Calhoun Station in pine seedlings. Spacing was the main difference in the plots planted. Another consideration given at the time was the harvesting of pine straw following needle cast each fall. The pine straw market was a viable and growing one at that time. Thinning at the recommended time and to the number of trees needed per acre to produce saw logs was a part of the plan, all of which was to be measured on a regular schedule. Planting was done in 1990 in open pasture land.
Spacings were: Each of these densities was replicated four times. All plots were treated the same as to pruning, that is, eight feet above ground level, or one-half the total tree height. There was no pruning in the control plots. Fertility rates and amounts were (1) no fertilizer (2) commercial fertilizer, and (3) broiler litter at two to four tons per acre. Diameter at breast height (DBH) was to be used for determining growth and response to the spacing and fertility. Other measurements to begin in the sixth year of growth, and continue until year 15 included the following: Stem diameter every two feet from the ground line to a height of 16 feet, to be taken once a year, along with double bark thickness taken for each stem diameter measurement Height of the tree to the base of the live crown, to be taken annually. Weight, quality, and analysis of mineral content of straw, collected in years six through 15. Potential environmental impacts on soil nutrient depletion, both micro and macro nutrients, and water quality, taken seasonally to check for surface water changes. NEXT: Part 2 - Fencing and adding the goats. |