Sustainable Whole Farm Grain/Silage Production Systems for the Southeast

Sustained economic viability and environmental quality of farms in the Southern Region can be improved by diversified whole farm systems that effectively integrate livestock and cropping systems. This project, conducted from June 1993 through April 1998, attempted to determine the potential of new systems, utilizing new or improved crop species adapted to the region, i.e., tropical corn (Zea mays L.), hybrid pearl millet [Pennisetum glaucum (L.) R. Br.], and white lupin (Lupinus albus L.), that are adapted to the unique edaphic and climatological conditions of the humid South.

In summary, data indicated that:
1. Wheat yields demonstrated a variable response to previous summer rotation crop, but were generally greater following soybean. However, equivalent yields were obtained following millet and tropical corn, provided the summer grain crops were fertilized with 120 to 180 lb N/acre.
2. Soybean yields were reduced from 11 to 23% following lupin.
3. Lupin silage averaged from 2.4 to 11.8 tons (35% DM) and grain yields averaged 0 to 34 bu/acre. The experimental design and N balance objectives required that lupin be grown in the same plots every year. Diseases, especially anthracnose (Colletotrichum gloeosporioides) and brown spot (Pleiochaeta setosa), were increased by the lack of rotation. Optimum planting time for lupin is 4 weeks before the first 28 degrees F freeze in fall. Lupin (even failed crops) demonstrated a positive rotation and N response for tropical corn and millet. Lupin are relatively insensitive to acid soils but respond to adequate P fertilization. Lupin as a green manure supplied sufficient N for a 20.5 tons/acre silage crop of tropical corn.
4. Tropical corn silage ranged from 4.9 to 26.8 tons/acre, dependent on previous crop and N fertilizer rate. Grain yields ranged from 24 to 100 bu/acre.
5. Millet silage yields ranged from 4.3 to 27.5 tons/A, dependent on location, N rate and previous crop. Following wheat, 120 to 180 lb N/acre was required for maximum yields. (54 bu/A). Dependent on location, previous crop, and N rate, millet grain yields ranged from 15 to 129 bu/acre. Millet yields were up to 43% greater following lupin than wheat. Bird predation is a problem on small acreages. Millet yields were greater when drilled. Optimum pH is 6.0-6.5 for millet and millet responds to high levels of soil P.
6. All three crops can be ensiled satisfactorily. Tropical corn and millet silage had similar energy and protein content to temperate corn silage and lupin silage was lower in energy but higher in protein than other silages. Dairy cows on lupin silage based diets had the same milk production as those on temperate corn silage diets while cows on millet and tropical corn diets produced less milk. Our results show that pearl millet is a potential silage crop and a viable feed grain crop for double-cropping systems in the southern USA. A new race of rust in 1993 curtailed late plantings of the crop, one of its strong points. A good multi-gene resistance to this race of rust has been developed and a new rust resistant hybrid with even greater grain yield potential than the variety used in this study (HGM-100) is scheduled to be commercially released, probably in 1999.

As a result in part from this project and satellite projects, there is a tremendous amount of interest in using lupin as a cover crop for cotton production in the Florida panhandle, southern Georgia and Alabama, South Carolina and North Carolina. Resource Seeds (Visalia, CA) is currently increasing a high alkaloid selection from 'Tifwhite-78' (a USDA-ARS release) white lupin seed for this purpose. The Auburn University cooperator, Edzard van Santen, is also increasing seed of a selection of high alkaloid 'Tifwhite-78' lupin to be used as a cover crop. A high alkaloid type would be a better choice for a cover crop/green manure in that alkaloids protect the plants from pests and some diseases. Also, there is research to indicate that high alkaloid lupin may suppress certain nematodes. Also, due to our efforts, Agicultural Resources International Seed Technology Division, Swedesboro, NJ, obtained distribution rights in the USA to market 'Lunoble' and 'Lumineux' white lupin from Agri-Obtentions, the seed company in France, which owns proprietary rights to these varieties. We furnished seed to the company for seed increase in September of 1997.

Based on public response to articles on background research for this SARE project, the use of lupin in products for human consumption is an area that should receive further research interest. The public seems to be keenly interested in this topic and a human food market would increase the value of the crop, making it more profitable for farmers to grow. Also, from observations that arose out of our research there is considerable interest in lupin seed to be used for wildlife food plots. This potential is being currently being investigated by an Auburn University wildlife biologist.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.