Assignment task: Five cropping systems were applied for 10 years (1935-45) to the experimental treatment fields and one field was left idle (not cropped or harvested, fallow). Soil erosion was measured over the ten years, and at the end of the 10 years, soil organic matter and aggregation were measured in each treatment. A crop uniformity test was also conducted: corn was produced on all of the treatment fields for two years. Assume that the same tillage equipment was used to plant all of the crops. The table summarizes a number of cropping systems performance indicators: i. soil loss over the 10 years, ii. average corn grain yields in the two years after the 10 years or cropping system history, iii. the percentage of soil organic matter and iv. the percentage of soil aggregation.
1. Based on what you have learned about how crop types and tillage influence soil, how do you interpret and explain the soil loss, soil organic matter and aggregation differences among the six cropping system treatments? Consider which crops are annuals, biennials, and perennials, and how crop life history and planting frequency can affect soil conservation and quality. Explain your answer.
2. How do you explain the differences in the corn grain yields following the 10 years of the cropping system treatments? Consider how the crops cultivated for the 10 years influenced the three soil quality indicators. In addition, consider how the different previous crops might have influenced other factors that can affect corn yield. Explain your answer.
3. Based on what you have learned about crop and soil management practices, are there other crop and soil management practices that may not have been implemented that could improve soil health and agroecosystem performance? Explain two other approaches you would recommend, why, and how the approaches would improve soil health and agroecosystem performance.
4. Responses should be 400-600 words in length. Be sure to include at least two references and corresponding in-text citations, two questions, and thoughtful comments on at least two other students' posts.