Available organic nitrogen Organic nitrogen is not available to the crop until it has been mineralized to the ammonium form by microbial action. The speed of mineralization increases with warm temperatures and adequate moisture, which promote microbial activity and will slow down to almost no activity when soil temperatures approach freezing. Nitrogen from solid manure […]
Manure and organic amendments contain two main forms of nitrogen (N): organic nitrogen and ammonium nitrogen (NH4-N). The nitrate nitrogen (NO3-N) in manure is negligible, however the ammonium portion in manure is converted to nitrate within weeks of application during the growing season. NH4-N and NO3-N are immediately available to a growing crop, similar to […]
Ontario labs accredited for OMAFA soil testing use similar methodology and report results with “as-is” or “as-applied” percentages or ppm for macro and micronutrients. Table 1 provides details for interpreting the results of a manure analysis and calculations used to determine available nutrients. OMAFA’s AgriSuite nutrient management software tools includes an organic amendment calculator that […]
There are many variables that impact manure composition. These variables include livestock type, stage of growth and ration, amount and type of bedding, type of manure storage and amount of liquids added (rain, wash waters, runoff etc.), length of time in storage, agitation, manure treatments (e.g., anaerobic digestion, aeration, additives, separation) and weather. Soluble nutrients […]
Manure is the by-product of livestock and poultry production. It includes the urine, feces, bedding materials, wasted feed, and sometimes wash water from livestock operations. The value of manure in crop production is often underestimated. In Ontario livestock generate over 25 million tonnes of manure annually. Manure contains all the nutrients needed by crops, but […]
Optimizing Crop Residue Management for Overall Profitability When and where should crop residue management start? It’s an ongoing and system-wide aspect of overall crop management, so choices such as crop rotation, fertilization and tillage feed into it. However, crop residue management generally starts with the combine. Combining crops without the proper equipment or setup can […]
Fall Herbicide Applications: Maximize Impact on Perennial Weeds Many farmers have seen the benefits of applying systemic herbicides in the fall, especially for the control of perennial weeds (Figure 1). Dandelion control can be improved by over 20% with fall application timings (Figure 2), while the population of other perennial species will be reduced and […]
Caution! Members of the sorghum family – sorghum, sudangrass, and hybrid sorghum-sudangrass – contain dhurrin, a glucoside that breaks down to release hydrocyanic acid, also known as prussic acid (hydrogen cyanide, HCN). A sudden disruption of growth such as frost, drought or cutting, causes prussic acid to be released inside the plant at a more […]
Identification True armyworm (also known as common armyworm), when full grown, are 4 cm (1 1⁄2 in.) long. They can vary in colour from dull-green to brown or black. Two distinguishing features are orange stripes bordered by a thin white line running laterally along the body and dark horizontal bands at the top of each […]
Identification Cereal leaf beetle (CLB) adults have metallic, blue-green wings, are approximately 5 mm (1/5 in.) in length, with a reddish-orange head and legs (figure 1). CLB eggs are football shaped and approximately 0.5 mm in length (figure 2). They are laid on the upper surface of the leaf, close to the midrib and start […]
Identification Cereal aphids are a complex of three different species that infest cereals. Bird cherry-oat aphids (figure 1) are the most common aphid found in Ontario cereals. These aphids are small, 2 mm (1/12 in.) or less. Adults are olive-green with patches of red-purple near the rear of the abdomen, between a pair of “tailpipes” […]
Summary Wheat is most susceptible to fusarium head blight (FHB) infection during the flowering period. Spores are carried from infected crop residue by wind or rain and splash onto the wheat head. Rainfall or heavy dew during this period then causes the spores to germinate and infect florets on the wheat head. Identification Symptoms of […]
Identification Stripe rust causes yellow to orange, blister-like lesions that are arranged in stripes on the leaf of the wheat plant (Figure 1 and 2). If left untreated, stripe rust can cause significant yield reductions. In previous stripe rust years, where growers had a high incidence of stripe rust that was not controlled through appropriate […]
Identification The primary symptoms of Barley Yellow Dwarf Virus (BYDV) include stunting and yellowing, reddening or purpling of the leaf tips (Figure 1 and 2). BYDV is often confused with nutrient deficiency or other environmental causes, or other virus diseases such as wheat spindle streak mosaic virus (WSSMV) or soil-borne wheat mosaic virus (SBWMV). Identifying […]
Introduction Lodging of cereal crops can be a major harvest challenge and can cause significant yield loss when it occurs early crop development. Variety selection, history of manure and organic matter levels, seeding dates and rates and disease infections all play a role in lodging susceptibility. There are significant varietal differences in resistance to lodging. […]