An Integrated Approach to a Growing Issue: The Effect of Sustainable Soil Management Systems on Maize Gene Expression
Open Access
- Author:
- Roach, Erika Danielle
- Graduate Program:
- Agronomy
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- March 13, 2012
- Committee Members:
- Surinder Chopra, Thesis Advisor/Co-Advisor
- Keywords:
- gene expression
cover crop
no-tillage
hairy vetch
abiotic stress
biotic stress
carbon metabolism
nitrogen metabolism - Abstract:
- To feed a growing population, food production must increase substantially in the coming years. In order to maintain the level of food production needed to feed the world’s population, yields need to improve for crops grown using sustainable soil management systems. Sustainable soil management practices such as no-tillage and cover crops expose plants to a different growing environment and different stresses than do conventional management systems. The objectives of this study were to determine the effect of hairy vetch cover crop, no-tillage, nitrogen side-dress fertilizer, and their interactions on crop and soil quality and the expression of genes involved in C and N metabolism and abiotic and biotic stress response in maize. Measurements of plant and soil quality and expression level of genes involved in C and N metabolism and plant response to abiotic and biotic stress were taken throughout the growing season. Gene expression in plants was affected by soil management practices. No-tillage preserved soil and plant moisture and led to decreased expression of drought-response gene Dhn1. No-tillage, without a cover crop, led to plants that experienced more nitrogen stress and decreased expression of genes involved in N metabolism at silking stage compared with tillage. The balance of drought and nitrogen stresses in plants in no-tillage and tillage treatments led to equal final yield. Plants in the treatment with a cover crop may have experienced more insect and pathogen pressure throughout the season and this resulted in increased expression of biotic stress-response genes but did not affect final yield. The treatment with a cover crop yielded higher than the treatment without a cover crop and using hairy vetch in a no-tillage system alleviated nitrogen stress in plants. Overall, it was determined that using no-tillage and hairy vetch is a best systems approach to sustainable agriculture. The results of this research emphasize the importance of integrating molecular and agronomic approaches to current crop production strategies in order to improve crop yield and soil quality to meet the food needs of the future in a sustainable way.