Soil management is not only imperative in sustainable farming but also aids in higher yields during the growing season. As a 5th generation farming operation, Jim McCullough Farms recognizes the importance of maintaining healthy soil. Techniques that are practiced during the season to achieve desired soil health include reducing compaction of the soil, crop rotation, composting, use of green manure, and beneficial tillage techniques.
Pore space in the soil is essential to the healthy growth of the potato plant. Soil compaction removes the pore space and reduces the ability for essential nutrients required during the growing season to reach the plant. The farm invests in wide, low pressure tires in order to distribute the weight of the equipment on the soil surface and reduce compaction.
The climate in the San Luis Valley is very dry. For that reason, it is necessary to have pore space in the soil to allow water to reach the plants. Field work is completed when the soil isn’t wet, allowing for aeration, thus prepping the land for irrigation.
Crop rotation keeps the soil fertile and reduces the amount of diseases, insects and weeds faced from year to year. When crops are rotated, soil organic matter content is increased. The organic material breaks down and stimulates beneficial microbes in the soil resulting in soil respiration.
Compost is applied in the fall. The enriched soil contains beneficial microorganisms that keep the soil well-aerated and can reduce the amount of water, chemicals, and inorganic fertilizers that are needed to grow healthy plants.
Green manure is used as mulch and a soil amendment. It decreases erosion, helps balance the pH of the soil and naturally deters weed growth.
Wind erosion is one of the most critical issues faced during the winter and early spring months in the San Luis Valley. It was determined that leaving the field rough with ridges 14 – 15” apart and mixing the straw from the prior year back into the soil has helped decrease the amount of soil lost during this time. If natural weather moisture does not occur after field work is completed, water will be applied to form a crust, which holds the soil in place during the windy months prior to planting.
Minimum tillage is practiced to increase soil aggregation which gives the plants a better root system and reduces soil erosion.
We grow Russet Norkotahs, which we typically plant in late April/early May and harvest in late August/early September. We store our potatoes in large, cool, dark bins for the rest of the season. This allows for a year-round potato supply from Colorado.