Donald J. Boquet

The history of the soybean crop in Louisiana is rather brief compared with cotton, sugarcane, rice and corn, which have been grown in the state for several hundred years. Louisiana has had extensive soybean production only since the 1970s. The story of the Louisiana soybean industry is one of initial success followed by decline and then a re-emerging industry. The initial production years were characterized by rapidly expanding acreage and profitable yields with few yield-limiting production problems. Soybean acreage went from virtually none to more than 3.4 million acres in less than 10 years, making soybean Louisiana’s most economically important row crop. Producing soybeans continuously on the same acreage in a mono-cropping production system to the exclusion of crop rotations was not sustainable, however. Today, we recognize that among the soybean producing states, Louisiana, because of its subtropical climate and unpredictable weather systems, faces the greatest challenge to a competitive and profitable soybean industry. The primary problems include a diversity of pests (diseases, weeds, insects and nematodes) and reduced soil productivity (low fertility, pH and organic matter) that affect yield and grain quality. Much too often, poor quality grain resulting from insects, pathogens and adverse weather reduces value and limits marketability, sometimes even preventing sale of grain. For Louisiana farmers, profitable soybean production is a combination of agronomic, economic and pest management challenges during each growing season.

Within 10 years of soybean expansion during the 1970s and 1980s, pest and soil fertility problems became severely yield-limiting. Most of the acres converted from other crops, pastures and forests to soybean production experienced low productivity. As quickly as acreage had expanded, it retracted as farmers responded to low yields and reduced profits. Planted acreages dropped from 3 million to 1 million in 1999, and the low point for soybean production in Louisiana was reached in 2001 when planted acreage was only 640,000 acres. However, 2001 was also a landmark year because it was the first year that soybean yield averaged more than 30 bushels per acre (up from 21 bushels per acre produced in 1981). Yields have not fallen below this level since that year. A second breakthrough for yield was attained only 10 years later in 2010 with production of a statewide record yield above 40 bushels per acre. Soybean grain sales were estimated at $568 million in gross income to Louisiana farmers in 2010.

The revival of the Louisiana soybean industry was no accident. It occurred because of a better understanding of agronomic and plant protection practices needed to increase productivity. Concurrent with the development of the state’s soybean industry during the past 40 years was the development of extensive soybean research and extension programs to support the industry, initially within land-grant universities and the U.S. Department of Agriculture. More recently, these efforts have been increased among private seed breeding companies. As the research articles in this issue of Louisiana Agriculture demonstrate, many of the potential impediments impediments that limit productivity or profitability of soybean from Louisiana farms are the focus of studies by LSU AgCenter scientists. It is appropriate to note that 90 percent of the AgCenter’s soybean research projects receive partial funding from the check-off dollars contributed from, and managed by, soybean farmers, thus ensuring that research is targeted to specific areas. This issue highlights many of the ongoing studies from AgCenter soybean research and extension programs. These studies concentrate on the many problems limiting production. These study result in new technologies, varieties, agronomic and pest management practices needed to grow profitable soybeans, which, in recent years, has resulted in a re-emergence of the Louisiana soybean industry. These articles illustrate the progress that has been made through comprehensive research programs that continue to support the progressive development of a Louisiana soybean industry that is competitive and profitable.

Successful soybean production begins with the availability of environmentally-adapted, high-yielding varieties. The varieties grown during the initial 30 years of the Louisiana soybean industry through 1995 were developed in the USDA and land-grant university breeding programs. During the 1970s and 1980s, the LSU AgCenter breeding program released several varieties specifically suited for producing high yield on Louisiana soils. Today, however, the AgCenter breeding program is focused, like other university breeding efforts, on introducing genetic traits for improved oil quality, resistance to diseases and pests, and maintaining yields in adverse environments. Soybean plants are being developed for production under extreme adversity from both biotic and abioitic causes and with greater utility to meet the needs of a growing world population. Complementary to variety development, the AgCenter supports a comprehensive variety testing program that evaluates more than 200 varieties on seven soil types annually. The AgCenter additionally supports an on-farm variety evaluation and verification program that extends directly into many parishes, which helps to further ensure that growers across the state have information to select the best possible varieties and practices to maximize economic returns.

To take advantage of the yield potential of adapted varieties, field management practices are constantly evaluated to determine the most effective means of integrating best management practices in a holistic approach to maximize the beneficial effects of agronomic and pest management inputs but, very importantly, minimize any harmful effects on the environment. AgCenter scientists have established formal collaborations to ensure that crop protection and soil management programs are not only effective, but also safe for the environment. In this issue of Louisiana Agriculture, for example, recently completed research on the green plant malady is described – a crop dysfunction that has been perplexing producers in Louisiana for many years and, more recently, has spread throughout Midsouth soybean fields. Through the efforts of an interdisciplinary team of AgCenter scientists, this malady was thoroughly described and many of the multifaceted causes identified. Farmers now have the information needed to manage and usually avoid losses from this significant production problem. Optimal management strategies also continue to be developed for native insect pests and for newly introduced species. The red-banded stink bug has been of special concern for its feeding habits that devastate seed quality and contribute to the green plant malady.

Yield losses from weed competition are a serious constraint to profitable soybean production in Louisiana. Herbicides are the only economical means of controlling the multitude of weed species in soybean fields. Without effective herbicides soybeans cannot be grown. Weed management has recently become even more of a critical concern with the development of weeds resistant to many herbicides used in Louisiana row crops. The extent of this serious problem and the approaches being taken to minimize herbicide resistance are covered in articles in this issue. Effective weed control measures and weed resistance to herbicides will always be a major concern of soybean producers, requiring continuing research because weeds will continue to evolve mechanisms of resistance in response to whatever control systems are used.

Producing high quality grain that is acceptable for processing into quality products for animal and human consumption – and can, therefore, be marketed without discounts – is the goal of soybean farmers. Achieving the goal of producing high quality grain and preserving that quality through harvesting and marketing is often difficult at best and sometimes is simply not possible under Louisiana weather conditions. Seed quality research initiated in 2010 with funding from the Louisiana Soybean and Grain Research and Promotion Board will help to mitigate some of these quality losses. Variety selection, thorough disease and insect control and timely application of harvest aids, when their use is dictated by environmental conditions, can each improve seed quality. Used together they will provide the greatest probability for maintaining seed quality under the prevailing climatic conditions in a given year.

Along with higher production of quality grain, research continues on new product development. Several articles in this issue describe ongoing research by LSU AgCenter scientists to expand functionality of the soybean by developing methods to extract and use bioactive components of both oil and protein. These methods add new uses that can be healthy additions to the diets of expanding world populations and add to the economic value of the soybean crop in Louisiana.

Louisiana soybean acreage may not, and probably should not, again attain the 3.1 million acre levels grown in the early 1980s. Such large acreages in one crop do not allow for crop rotation practices that are needed to maintain productivity. Sensible use of appropriate practices and technology, however, allow soybeans to once again be the largest acreage crop in the state. With increases in yield and quality, fostered by the research and extension programs in the LSU AgCenter, soybeans will likely remain one of the foremost agronomic crops in Louisiana.

Donald J. Boquet, Professor of Agronomy and Jack and Henrietta Jones Endowed Professor, Macon Ridge Research Station, Winnsboro, La.

(This article was published in the spring 2011 issue of Louisiana Agriculture magazine.)