Soybean Yield Response to Rhizobium Inoculation on Converted Grass Pasture

Much of the soybean plant's nitrogen requirement is supplied through nitrogen fixation when atmospheric nitrogen is converted into a usable form for the plant. Nitrogen fixation is critical for producing higher yield in soybean. For nitrogen fixation to occur, nitrogen-fixing bacteria (genus Rhizobium) need to be present in the soil. If soils do not already contain a high population of Rhizobium, these bacteria can be added either as a liquid or granular peat inoculant, or as a peat-based powder. The different forms can be seed applied or used in-furrow.

Evaluation of Foliar Fungicides and Insecticides on Soybean

Use of foliar fungicides and insecticides are an effective strategy for managing foliar diseases on soybean. There are many different fungicides and insecticides available for use currently in Iowa. Iowa State University personnel assessed the success of fungicides and insecticides across Iowa. This study was conducted at six locations: Sutherland (NW), Kanawha (NC), Nashua (NE), Ames (central), Crawfordsville (SE), and Lewis (SW) research farms (Figure 1).

Placement Methods of Phosphorus and Potassium for Corn and Soybean Managed with No-till and Chisel-plow/Disk Tillage

No-till management limits the incorporation of crop residue and fertilizer with soil resulting in wetter, colder soils and the accumulation of organic matter, phosphorus (P), and potassium (K) near the soil surface. Banding of P and K could be more effective than broadcast fertilization by counteracting stratification, applying nutrients in the root zone (starter effect), and minimizing reactions with the soil that may reduce their availability to plants. Therefore, this long-term study was established in 1994 to evaluate P and K fertilizer placement methods and grain yield of corn-soybean rotations managed with notill and chisel-plow/disk tillage.

Effect of Date of Planting on Soybean Sudden Death Syndrome

The objectives of this project was to study the effect of planting date on the onset of soybean sudden death syndrome (SDS). It is believed, that avoiding planting soybeans into wet cold soil may delay or lower the severity of SDS. Planting date for soybeans is important and can have a large effect on yield potential.

Elite Soybean Test—South

The purpose of this test was to evaluate the experimental elite soybean lines adapted to southern Iowa. The 2011 Elite Test included commodity—yellow hilum soybeans and large seed and high protein beans, along with commercially grown varieties released by Iowa State University tested for comparison of agronomic traits. These varieties are used in the production of soy foods

Effects of Headline® on Soybean Aphid Resistant and Susceptible Varieties

With the introduction of soybean aphid-resistant varieties, growers have another option for controlling the pest. This study was designed to see how each variety responded to Headline® fungicide at different application timings.

A Comparison of Soybean Seed Treatments

Seed treatment options are available to manage various fungi, insects, and nematodes that can damage soybeans before, during, and after emergence. These treatments are potentially beneficial for stand establishment and for protection against soybean cyst nematode (SCN). However, these seed treatments represent an additional cost to the producer.

Soybean Aphid Efficacy Evaluation

Soybean (Glycine max), grown in Iowa and most of the north central region of the United States, has not required regular insecticide use. The soybean aphid, Aphis glycines (Hemiptera: Aphididae), causes yield losses from direct plant feeding, and has been shown to transmit several plant viruses. In Iowa, soybean aphid can colonize soybean fields in June and has developed into outbreaks in July and August capable of reducing yields by nearly 40 percent.

Soybean Aphid Efficacy Evaluation

Soybean, Glycine max (L.), grown in Iowa and most of the north central region of the United States, has not required regular insecticide usage. The soybean aphid, Aphis glycines (Hemiptera: Aphididae), causes yield losses from direct plant feeding, and has been shown to transmit several plant viruses. In Iowa, soybean aphid can colonize soybean fields in June and has developed into outbreaks in July and August capable of reducing yields by nearly 40 percent.