Non Technical Summary
With fewer of the restrictions that hinder production in areas more adjacent to urban populations, Arizona has seen an increase in livestock industry. Our desert clientele see dairy and beef as alternatives that allow them to diversify and maintain profitability. However, hot summers induce alfalfa to suffer a "summer slump" that slows growth and reduces forage quality. The most common annual summer crops to supplement forage demand, sudangrass and maize, produce lower quality forage, require more fertilizer, and often have adverse effects on subsequent rotational crops. Growers have asked that we find potential solutions that would sustain forage production and improve crop diversity and productivity. We will investigate the potential of several legume crops as forage, their fit in current production systems, and intercropping these legumes with maize in Arizona. Alternative legume forage crops, such as lablab (Lablab purpureus), cowpea (Vigna unguiculata), and pigeonpea (Cajanus cajan) will be planted in early summer and regularly harvested to evaluate quality and yield. A bare ground treatment will also be included in the study as a control, and all treatments will be followed by a fall planting of wheat. Pre- and post-plant soil nitrogen will be measured, as well as the nutrient status of the wheat crop. Field experiments at research stations in the 1st and 2nd year will quantify yield and quality of these forage crops and their effects on the following rotational crop. We will work with participating growers to conduct an economic analysis to help choose the best alternatives for farms typical of the region. After legumes with high quality and yield are identified in the environment of Arizona and southern California, on-farm trials will be conducted in the 2nd and 3rd year with participating growers to investigate the potential of the legumes crops alone and intercropping these legumes with maize to improve the quality of grass forages. Research findings will be disseminated to growers and other agricultural professionals by field days, presentations at grower meetings, one to one communications, and extension publications. Growers will participate by providing fields for trials, helping develop experimental plans and give feedback on results, and advise research scientists on the future direction of the project. We expect that growers will adopt more annual legume forage crops into their current cropping system to increase sustainability of by improving soil fertility, increasing growers' profitability, and increasing system diversification in the region.
Animal Health Component
Research Effort Categories
Goals / Objectives
Decades of research has not found a way for desert alfalfa to avoid "summer slump," which is why growers want to see experiments to investigate the potential of alternative summer legumes and intercropping these legumes with maize. Therefore, the general objective of the present proposal is to assess the introduction of summer legume forage crops into current cropping system in Arizona and their effects on growers' profitability. The specific objectives include: 1. Consult with growers to select alternative forage crops. 2. Work with growers and other clientele to conduct replicated experiments to provide them the needed knowledge to evaluate forage and rotation options. 3. Conduct on-farm experiments and field days to help growers evaluate the practicality of alternatives and intercropping the alternatives with maize for their specific farm enterprise. 4. Perform economic analyses to select the best option for growers. 5. Raise awareness of rotation options and experimental results through field days, grower meetings, in county newsletters and other publications, and on websites. Expected outputs include that growers will be more willing to incorporate legume forage into their current cropping systems or to intercrop these legumes with cereal silage such as sudangrass or corn. We anticipate that incorporating legumes into current systems will ultimately prove to be economically feasible and that growers will benefit from the diversified cropping systems as a result of information obtained from the proposed project.
One-to-one meetings with growers will be established from the beginning of the project. The purpose of these initial meetings is to get better acquainted with growers' current farming practices and difficulties, and to consult with growers to select potential alternative legume crops. Three or more legume species, including lablab, pigeon pea, cowpea (Cultivar CC-36 and Iron Clay) will be planted at Maricopa Ag Center in AZ in June of 2008 and 2009. A bare ground control will also be included in the study. The forage crops will be managed using best management practices that participating growers deem practical. Only phosphorous fertilizer will be applied to the legumes when pre-plant soil analysis shows that it is necessary. At 3 months after planting, forage crops will be harvested for yield evaluation. Forage quality will be assessed by analyzing nutrient content (crude protein, ash, neutral detergent fiber (NDF), acid detergent fiber (ADF)). Following forage crops, wheat will be planted as the rotational crop in November of 2009 and 2010. Growth and yield of the wheat crop will be recorded for analysis. Soil nitrogen content will be measured pre- and post-planting of forage crops and wheat. Nutrient status of wheat will also be monitored periodically to investigate the effects of legume forage crops on soil nutrients and wheat yield. On-farm experiments will be conducted in one or two forage growers' fields in 2010 and 2011 to investigate the potential of incorporating the best-fit legume crop and intercropping the legume with maize. The five treatments include legume monoculture, maize monoculture, and three combinations of the legume with maize. Summer forages will be planted in late June of 2010 and 2011 and harvested in mid-October. The rotation crop will be winter wheat. Biomass growth of summer forages and soil fertility will be monitored during the experiment. Forage yield will be recorded and forage quality analyzed. A field day will be conducted in the middle of September to invite a larger group of growers inform them on the progress and adoptable results from the project. Detailed management records for the study sites will be kept by the researchers and used to evaluate the total cost and profitability of incorporating the summer forage crops into the cropping systems and intercropping legumes and grass forage crops. We expect that this economic analysis will help growers understand the profitability of incorporating legumes forage crops into their cropping systems. Grower education will begin with consultation with growers before the project and continue throughout the project to include face-to-face communication with growers, articles, and talks discussing the current state of knowledge. Information dissemination will then continue with field days at both research stations and farms to disseminate information to growers and other agricultural personnel.