No description available.

Thesis (M.S.)--University of Michigan, 1962.

No description available.

Thesis (Ph. D.)--University of California, Santa Cruz, 1996. / Includes bibliographical references (leaves 211-288).

Production costs and production rates for harvesting hardwood pulpwood in western Virginia were empirically studied. The harvesting operations of felling, bucking, skidding, loading and delay were individually and collectively analyzed. Forty operators were studied during the period July-September 1965. Average production time for all operators to process 1000 pounds of wood from the stump to a loaded transport device was 39.8 man-minutes, 8.0 power saw minutes, and 3.8 tractor minutes. Average cost for the total operation was $1.29 per 1000 pounds. Operators studied were stratified by amount of equipment used and productivity in truckloads per day. Variation within strata obscured most differences between strata. However, the data indicated that two load per day operators had a lower cost per 1000 pounds than the one load per day operators. Recommendations for improved harvesting efficiency center on improved organization of the harvesting processes, such as temporary storage, rather than on larger or different equipment. / M.S.

In August 2019, Prima-Sekunda is about to be introduced, a new classification system for the classification of pulpwood during surveying to industry. This new classification system should be more time and cost effective and at the same time offer the industries commodity volume with better quality. The purpose of this study was to compare if there was any difference in the economic outcome with the new Prima-Sekunda compared to today's classification system when measuring pulpwood. Based on the 95 piles measured, it appeared that today's classification system gives somewhat better paid than Prima-Sekunda due to the prices for Prima-Sekunda which are initially set slightly lower than today's pulpwood price. The introduction of Prima-Sekunda should be price neutral, which means that the prices for Prima-Sekunda as shown in the current study must be reasonably equal to the current pulpwood price for this goal to be materialized.

Fertilizer P fixation and fertilizer N losses in soils may be reduced through additions of polyphenolic compounds. The influence of ammonium lignosulfonate (NH$ sb4 sp+$-LS) on triple superphosphate (TSP) efficiency was investigated in a soil incubation study using three Quebec soils and in a growth bench study using one soil. For the incubation study, soils were analyzed for pH and P extractability, as a function of NH$ sb4 sp+$-LS rate and time. In the growth bench study, TSP and NH$ sb4 sp+$-LS were applied at varying rates and corn (Zea mays L.) dry matter yields and nutrient compositions analyzed. Similar studies were conducted in subsequent growth bench studies, to evaluate combinations of NH$ sb4 sp+$-LS, diammonium phosphate (DAP), and urea on two soils. / Ammonium LS increased soluble P levels when applied with TSP. The effect was most significant in fine textured soils, and increased with time. This improved P availability to plants, without affecting growth. The optimum NH$ sb4 sp+$-LS:P$ sb2$O$ sb5$ application ratio was approximately 2.8:1. Ammonium LS did not improve availability of DAP-P in either of the subsequent experiments, nor did it improve urea fertilizer efficiency. Some NH$ sb4 sp+$-LS-urea-DAP formulations did, however, improve corn growth beyond that obtained when only urea and DAP were applied in combination. In nutrient amended soils, applying NH$ sb4 sp+$-LS DAP was detrimental to growth and, for some application rates, reduced nutrient uptake.

Lignosulfonate (LS), a by-product of the pulp and paper industry, may have the potential to increase fertilizer N availability by acting as a urease and nitrification inhibitor. Four consecutive laboratory studies were conducted to evaluate the behavior of LS in agricultural soils. The effects of various types and rates of LS on soil respiration and soil N dynamics were determined. Effects of LS in combination with fertilizers on microbial activity and N dynamics were measured. Due to the high water solubility of LS a leaching column study was conducted to determine the potential leaching of LS. / Higher rates (20% w/w) of LS initially inhibited microbial activity. Generally LS was relatively resistant to degradation by soil microorganisms and small proportions of added LS-C ($<$2.1%) were leached from the soil columns, but leaching was a function of soil and moisture regime. Recovery of added mineral LS-N from soil treated with LS was low ($<$41%). Mineral N recovered from LS plus fertilizer amended soil was higher than recovery from corresponding fertilizer treatments. Lignosulfonate reduced urea hydrolysis and the proportion of added N volatilized as NH$ sb3$-N from a LS plus urea treatment. The mineral N pool from LS plus fertilizer treated soils had significantly lower NO$ sb3$-N concentrations than corresponding fertilizer treatments. Nitrification inhibition was believed to have been due to high fertilizer concentrations. At reduced urea and LS concentrations, LS decreased NO$ sb3$-N recovery in one of four soil types. However, reduced recovery may not have been from nitrification inhibition but possibly from denitrification or chemical reactions between N and phenolics from LS.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 6 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2000. / Härtill 3 uppsatser.