Die fossile Flora der Permischen Formation / [book]

H. R. Göppert
1864 unpublished
ntroduction oiO ; UJ O o :~C O / Fertilizer placed in the planting hole increased height growth of ponderosa pine {Pinus ponderosa Dougl. ex Laws.) early in the life of the plantation. Later broadcast applications of fertilizer may have had little effect on growth. Wider spacings produced larger trees but less volume per acre than narrower spacings after average tree height exceeded 7 feet. Fertilization produced larger trees and more volume per acre at each spacing. Keywords: Nutrient
more » ... ity, indirect fertilization effects, root development. Banding fertilizer beside the row and below the surface is often more efficient than broadcast application for cultivated annual farm crops. Farm crops have rapidly developing root systems that use a large volume of soil, and competing vegetation is greatly reduced or eliminated. In contrast, tree seedlings use a smaller volume of soil the first year after planting, and competing vegetation usually surrounds the planted trees. Broadcast application of fertilizer to newly planted seedlings may increase growth of competing vegetation, and only a small fraction of the fertilizer comes in contact wiih the slowly expanding roots of the tree seedlings. Placement of the fertilizer in or near the planting hole (the forestry equivalent of banding) increases the probability of uptake by the tree seedlings, provided the tree roots are not damaged. Because trees are long-term crops, slow-release fertilizers may be more efficient than those used in standard agricultural operations. Austin and Strand (1960) reported increased growth and good survival of Douglas-fir {Pseudotsuga menziesii (Mirb.) Franco) seedlings near the Oregon coast when fertilizer pellets containing slowly available phosphorus (P), and nitrogen (N) were placed in the planting hole. More recently, briquets of slowly available N, P, and potassium (K) with calcium (Ca), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) placed in the planting hole seemed to increase first year Douglas-fir seedling growth without decreasing survival in southwestern Oregon (Atalla 1987) . Another study in southwestern Oregon showed that fertilizer placed 6 inches deep and 3 inches downslope from the Douglas-fir seedlings produced large increases in growth for 2 years after planting. The best response in that exploratory study was from 20-10-10-10 plus Ca (Hass 1987) . Porada (1987) also P.H. COCHRAN is a soil scientist, R.P. NEWMAN is a forestry technician, and JAMES W. BARRETT is a research forester (retired),
doi:10.5962/bhl.title.83833 fatcat:gaxhpgduojfolndhvrmxyupkry