Fresh Ideas for Dryland Farming

Using conservation tillage and crop diversification for better soil

Sleeping Ute Mountain dominates the landscape of the Four Corners region. However, Abdel Berrada, research scientist at the Southwest Colorado Research Center is doing anything but resting. He is tirelessly working to keep ahead of the needs of the agricultural community of the Colorado Plateau with his research on sustainable dryland cropping systems.

Farmers in the semi-arid environment of the Four Corners region face some unique challenges. The elevation is relatively high, around 6, 000 feet, making for a short growing season. Killing frosts occur late in the spring and early in the fall. The modest amount of rainfall comes later in the growing season than in most areas, creating another stress. The soil's relatively low organic matter, and steep slopes contribute to erosion with summer storms. Yet the region's pinto bean and alfalfa crops are known for their high quality – a benefit of the cool, arid environment.

Together with Gary Peterson, professor of soil and crop sciences at Colorado State, Berrada is taking a systems approach to develop sustainable dryland farming practices for southwestern Colorado and southeastern Utah. He is evaluating the use of conservation tillage and crop diversification to improve soil quality and increase yields.

Traditionally, the dryland farmers of the Southwest utilize systems of winter wheat followed by dry beans, or winter wheat followed by a year of fallow. To store moisture and control weeds, the fields commonly are disked and plowed after the fall wheat harvest. The fields often are worked two to five more times in the spring and summer with a field cultivator before planting dry beans. The resultant removal of the crop residue leaves the soil at risk of erosion.

There also is an economic trade-off with both traditional systems. With the wheat-fallow system, the land is only able to produce one crop every two years. The wheat-bean system tends to sacrifice some wheat productivity because the beans force a later-than-optimal planting of the winter wheat.

Berrada believes there may be better options. With a three-year grant from the USDA's Western Region Sustainable Agriculture Research and Education Program, Berrada is looking at several different approaches. He's comparing the traditional methods with options such as minimum tillage, alternative crops, and two, and three-year fallow cycles in numerous combinations. Application of fertilizer and weed control methods are also being tested. "We are here to experiment," explains Berrada. "We can make mistakes and it's okay." Farmers can't take the risk.

Crops Berrada is testing in the systems include winter wheat, pinto bean, oat, corn, safflower, alfalfa, and chickpea. He's combining these crops in various rotations with different tilling practices and cycles of fallow. Berrada is looking for combinations that create optimum yields, minimize weed problems, make effective use of water, add nutrients to the soil, and reduce the risk of erosion. Since the real world is Berrada's laboratory, every year's weather pattern introduces a new variable. In addition, the economics of the systems need to be considered. The price of a crop, the price of getting it to market, additional equipment, and regional infrastructure are all concerns. Sorting out the benefits and detriments of the combinations is complex and time-consuming.

Chickpeas, commonly known as garbanzo beans, hold some promise as an alternative to pinto beans for the southwestern farmers. Chickpeas are attractive because they utilize the same farming equipment and infrastructure as the pinto beans the area farmers already are producing. In addition the chickpea is more frost-tolerant, allowing for earlier planting and consequently earlier harvesting than pinto beans. This allows the winter wheat to be planted early in September, when it's most appropriate. Bob Hammon a research associate at the Western Colorado Research Center at Fruita figures, for each day winter wheat planting is delayed beyond September 1 there is likely to be a one percent reduction in wheat yield.

As he completes his second season of research under his Sustainable Agriculture Research and Education Program grant, Berrada feels he's just beginning on the research. "When you're working with crop rotations, you really need several years because it takes a long time to see changes in soil quality and pest dynamics," Berrada says. "That's probably why there are not a lot of cropping systems experiments out there."