Winter wheat management and wheat-row crop combinations for grain, silage and biomass production

Samantha Suellen Shoaf, Purdue University

Abstract

Winter wheat (Triticum aestivum L.) yield in Indiana is highly dependent upon environmental factors in the growing season and the management imposed by the producer. The objectives of the first study, located in Evansville and West Lafayette, Indiana in 2009 and 2010 were to determine the effects of seeding rate, nitrogen fertilizer, seed treatment-insecticide, foliar insecticide and foliar fungicide treatments on responses of seven varieties of soft red winter wheat. Wheat varieties did not vary in their responses to management inputs in either year or location. A second topdress application of nitrogen fertilizer (increasing N rate from 140 to 190 kg N ha-1 at Evansville and from 132 to 176 kg N ha-1 at West Lafayette) led to an increase in yield in challenging years, though this effect was reduced in highly productive environments. The yield increase was not associated with a decrease in grain quality measured by protein content, milling and baking qualities. In addition, economic analysis of the production systems showed that in high producing years and locations, investing in additional nitrogen decreased profit. In challenging environments, the higher investment in both seed and nitrogen resulted in higher annual net returns on both a per land area and per unit of grain yield basis. In the second study, the primary objective was to determine whether winter wheat based cropping systems in the Midwest have the potential to produce grain, forage or biofuel feedstock that is profitable. Fifteen winter wheat based double cropping systems and five single crop systems were studied near West Lafayette, Indiana in the 2009 and 2010 growing seasons to measure the impacts of no-till planting into wheat stubble and delayed planting on grain and dry matter yield, forage quality and potential energy yield. Winter wheat was harvested at boot, heading and at grain maturity stages as either whole plant silage or grain plus straw. The second crops tested were corn for grain, whole-plant silage corn, grain sorghum, sweet sorghum, silage sorghum and soybean. Each of these double-crop species were seeded on at least two planting dates as soon as possible after wheat harvest. Budgets were developed to gauge the profitability of the systems, and liquid fuel potential and total energy content of each system were assessed using conversion values from recent literature. This study found significant dry matter (DM) yield losses associated with planting grain corn, silage corn, and silage sorghum (but not soybean) into wheat stubble compared to bare ground. Differences in protein and fiber content, and digestibility were a function of double-crop species and planting dates. Enterprise budgets revealed that single crop systems or double cropping wheat with soybean were most profitable at the first planting date. At the second planting date, the ensiled winter wheat and soybean double-crop system was profitable in both years, while the silage sorghum and sweet sorghum double crop systems were profitable in one of the two years. At the third planting date, all five systems generated losses in 2009, but the soybean and silage sorghum double-crop systems generated a profit in 2010. All cropping systems were assessed for total energy yield, measured by total heat of combustion (GJ ha-1). The maximum energy yielding systems at each planting date were wheat greenchop plus silage sorghum, wheat silage plus silage corn, and winter wheat grain/straw plus silage sorghum for the three wheat harvests, respectively. Total heat of combustion (GJ ha-1) trends followed with those observed for liquid fuel in the form of fermentation or cellulosic ethanol conversion. Selected alternative cropping systems based on winter wheat were highly productive in terms of tonnage, economic and energy yields, but the overall system productivity was very dependent on the crop management plus harvest options adopted in both wheat and any crops that followed.

Degree

Ph.D.

Advisors

Snyder, Purdue University.

Subject Area

Agronomy

COinS