Interpreting the available nutrients in a fertilizer analysis Whether you are using a commercial fertilizer, organic amendments like manure or compost, or fertilizer by-products from industrial sources, it’s critical to know the nutrient analysis of the product. Analyses for agricultural nutrient sources may come in several different ways: When using a nutrient fertilizer source that […]
Potassium is the most important macronutrient required for soybean production in Ontario. Many Ontario soybean fields show potassium deficiency symptoms each year due to the large amount of potassium soybeans require, and the inability of soybean roots to take up potassium in dry soil conditions. Symptoms include yellowing and eventually browning of the margins of […]
Sulphur (S) is an essential nutrient necessary for plant growth. It plays an important role in nitrogen fixation, photosynthesis, and protein formation. Over the past decades, air-borne S emissions have drastically reduced in the Great Lake Basin, reducing the amount of S available to crops. Much like nitrogen, S moves downward with soil water through […]
Nitrogen (N) fertilizers are not usually required for soybeans as they obtain most of their nitrogen through biological N fixation and residual soil N reserves. See factsheet, Inoculation and Nodulation. Annual inoculation with the rhizobia Bradyrhizobium japonicum, ensures adequate nodulation and has provided a small yield benefit even in fields with a history of soybeans […]
Nutrient Deficiency Symptoms Causes of Deficiency Effect Photo Nitrogen Pale green plants Appear first and are more severe on older leaves since nitrogen is a mobile nutrient in plants Consistent across leaves (veins are also pale) Poor nodulation Excessive rainfall, causing nitrate leaching or denitrification due to prolonged standing water Temporary deficiency symptoms can occur […]
Compared to corn and wheat, soybeans are more prone to poor stand establishment because the seedling must pull the cotyledon seed leaves through the ground to emerge. Deciding whether it is worth replanting a poor stand can be difficult because plant stand reductions are rarely uniform. Often, it is best to treat parts of a […]
Land rolling helps conserve moisture and prepare a field for harvest. If conditions are very dry, rolling can improve emergence from moisture conservation and better seed-to-soil contact. Rolling can help level the soil and push rocks into the ground, making it possible for the combine header to do a better job. Small yield gains have […]
A seeding depth of 3.8 cm (1.5 in.) is generally a good target depth for soybeans. Seeding depth when planting early into no-till conditions can often be reduced to 2.5 cm (1 in.) if there is sufficient soil moisture. However, due to the high-water demand for germination, plant 1 cm into moisture (0.5 in.), but […]
Soybeans yield well over a wide range of seeding rates and final plant stands. Soybeans will compensate for thin stands, assuming weather conditions allow for strong growth. Higher plants stands are necessary in shorter season areas and clay soils compared to southern regions with lush growing environments. Excessive seeding rates add unnecessary cost and increase […]
Row Width Soybeans thrive under a wide range of row widths, especially in the long-season regions of Ontario. Row width selection is influenced by numerous factors, including tillage system, equipment suitability, weed problems, soil conditions, white mould pressure, and planting date. In Ontario, the majority of soybeans grown are solid seeded (19 cm or 7.5 […]
In recent years double cropping soybeans has become more common. In the past, double cropping was mainly attempted after winter barley or pea harvest in July. Now, double cropping after winter wheat has become more common in southwestern Ontario. Double cropping can be successful if soybeans are seeded early enough with adequate soil moisture for […]
Planting Date Planting date is one of the most important management tools available to maximize yield potential. Late seeded crops do not have adequate time to “catch up” with early seeded plants in most of Ontario, see figure 1. Figure 1. Vegetative plant growth differences based on planting date. Plot on left was planted in […]
Biological N fixation Biological N fixation converts gaseous nitrogen in the air (N2) to a form of nitrogen the plant can use, known as ammonium (NH4+). In legumes, symbiotic nitrogen fixation occurs when rhizobia invade the root hair and form a nodule on the root, see figure 1, Soybean Nodules. Rhizobia are a specific group […]
Knowing the quality of the seed being planted is critical to establishing a healthy crop. Certified seed is a guarantee of purity and germination standards. The quality of “farm-saved” bin-run seed is not known unless the germination is tested at an accredited seed lab prior to planting, see Factsheet, Ontario Laboratories Offering Custom Seed Germination […]
Soybeans are a photoperiod sensitive crop, meaning they flower based on the number of hours of sunlight in a day as well as temperature. Genetics, temperature, and hours of sunshine all play a role in when soybeans begin to flower and how fast they will mature in the fall. Soybeans typically begin flowering at the […]