Theses and Dissertations at Montana State University (MSU)
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Item Effect of mechanical and biological enhancements on erosion at high elevation disturbed lands(Montana State University - Bozeman, College of Agriculture, 2002) Winking, Susan RheaItem Long run effects on soil organic matter of various cropping systems in north central Montana(Montana State University - Bozeman, College of Agriculture, 1984) Clarke, AndreaItem Characterization of rangeland and cropland Natrargids(Montana State University - Bozeman, College of Agriculture, 1994) Sieler, David JamesItem Adaptation of Australian ley farming to Montana dryland cereal production(Montana State University - Bozeman, College of Agriculture, 1982) Koala, SaidouItem Understanding carbon sequestration in north central Montana dryland wheat systems(Montana State University - Bozeman, College of Agriculture, 2013) Feddema, Ryan Patrick; Co-chairs, Graduate Committee: Perry Miller and Richard E. EngelAgricultural management practices that reduce tillage and/or increase crop intensity have been shown to promote soil carbon sequestration in many regions of the Great Plains. Comparatively little information is available on the impact of these practices on soil organic carbon (SOC) in Montana's semi-arid climate. The objective of this research was to measure rates of change in SOC in cropland for north central Montana's Golden Triangle related to conversion of crop-fallow to annual cropping, conversion to no-till management, and the implementation of both simultaneously. A second objective was to measure differences in soil microbial biomass carbon (SMBC) as an "early indicator" for soil carbon accrual after six years of management. Field experiments were established at six farm sites in fall 2002. Soil organic C was not affected by the treatments at three of the six sites after six years (2002-2008). Three of the six sites had soil carbon accrual associated with annual cropping ranging from 0.19 to 0.53 Mg ha -1 yr -1. Only one site showed soil carbon accrual associated with no-till management, accruing 0.26 Mg ha -1 yr -1. It proved unreliable to make quantitative comparisons for samples from different collection times using SMBC because stored soil samples had diminished SMBC correlated with months in storage, making it impossible to compare accurately freshly obtained SMBC with earlier baseline values from stored soil samples. It was concluded that annual cropping is likely to increase SOC in many instances; however a longer study period may be required to understand SOC response to soil management in this region.Item The Conservation Reserve Program and future use of enrolled land in Montana(Montana State University - Bozeman, College of Agriculture, 1992) Sheard, Michael David; Chairperson, Graduate Committee: James B. Johnson.The Conservation Reserve Program (CRP), as authorized by the Food Security Act of 1985 is a voluntary cropland retirement program which relies primarily upon positive economic incentives to farm operators in order to entice them to convert cropland considered highly erodible or otherwise environmentally sensitive into a conserving use for a ten-year period. Through 1989, Montana farm operators enrolled nearly 2.7 million acres of cropland into the CRP. The first CRP contracts were entered into in 1986 and thus will expire in 1995. Under current policy, once the ten year period is over, cropland enrolled in the CRP can be returned to annual cropping, can be used in some alternative commercial use such as haying or grazing, or can remain in a conserving use. There is much concern in Montana and other states over how the future use of these acres could affect commodity prices, farm incomes, government outlays, rural economic activity, and environment quality. This study examines the factors to be used by individual Montana CRP contract holders upon contract expiration to decide the disposition of their CRP land among the alternative uses. A firm level mean-variance decision model is used to incorporate the risk involved with each alternative. The model also considers any one-time start-up costs that may be incurred to convert CRP acres into an alternative use. Test results using survey data from Montana contract holders suggest that very few CRP acres in Montana will remain in a conserving use. Most respondents indicated that they plan to either return all of their CRP acreage to annual cropping, or will hay/graze all of the acreage. The results suggest that the greater the percentage of income derived from range livestock, the more likely the CRP land will be hayed or grazed. Similarly, the greater the percentage of income derived from cropping, the more likely the CRP land will be returned to annual cropping. The evidence is that more CRP land will be hayed or grazed on operations that currently have haying/grazing activities, or that have physical attributes to facilitate haying/grazing activities.Item The economics of terraces in the Peruvian Andes : an application of sensitivity analysis in an integrated assessment model(Montana State University - Bozeman, College of Agriculture, 2002) Valdivia, Roberto Oscar; Chairperson, Graduate Committee: John M. Antle.Land degradation is a global constraint to economic development in countries such as Peru that have a complex topography where soil erosion is an important problem. Governmental and private institutions are promoting adoption of soil conservation practices such as construction of slow formation terraces, yet they lack accurate estimates of the private and social benefits and costs of these investments. The objective of this thesis is to provide a better understanding of the economics of terrace investments by (1) developing a method to conduct a sensitivity analysis of an integrated assessment model designed for the agricultural production systems in Peru, and (2) conducting an economic analysis of the effects of terraces on productivity and their economic implications. The Tradeoff Analysis software was used to implement an integrated assessment model and to conduct a sensitivity analysis of terrace investments in a watershed in northern Peru. Key parameters in the analysis are: erosion and terrace effects on productivity; interest rates; terrace maintenance and investment costs; and time to achieve terrace maturity. The analysis shows that the proportion of fields on which terraces are a profitable investment can be highly sensitive to key parameters, thus demonstrating the importance of sensitivity analysis to understand and interpret policy implications derived from integrated assessment models. The analysis also verifies the hypothesis that physical and economic heterogeneity are important determinants of terrace profitability. Terraces were found to be most profitable on more steeply sloped fields, implying that farmers have incentives to invest in terraces where both private and social returns are the highest.