With the cold winter that we have had, a slow start of insect development may occur. Many of the acres planted in Ontario have been planted with neonicotinoid insecticides. With the current debates over neonicotinoid insecticides, the best strategies to control pests is to start with a good knowledge of crop pests. By understanding early […]
Nitrogen management has always been a challenge in high nitrogen demand crops such as corn and winter wheat.
The three pathways that can contribute to significant nitrogen loss are:
- Volatilization (loss of ammonia nitrogen to the atmosphere from the soil surface),
- Denitrification (which occurs when soils are saturated and in an anaerobic environment) and
- Leaching (downward movement of nitrate nitrogen out of the rooting zone due to excessive rains)
The challenge has always been to make nitrogen available when the crop needs it and minimize the exposure of nitrogen to the weather scenarios that contribute to N loss. Consider the nitrogen response relationship for corn and winter wheat (below):
Corn nitrogen response curve
(Adapted from Richie, et.al, 2005, How a Corn Plant Develops).
We often apply nitrogen early in the season before the crop actually utilizes it. For example, the demand for nitrogen in corn is at its peak at about the V10 growth stage (often around early to mid-July). Split-applying nitrogen has been a reasonably effective way to reduce the risk of nitrogen loss, however, with added application costs. Read more
Increased interest in micronutrients
When it comes to applying micronutrients, understanding the different forms that they can come in is very important to know. There is an increased interest in micronutrients with today’s growers. Many growers and advisors realize that these can be a major limiting factor in crop growth. In order to increase yields, the levels in the soil of micronutrients need to be monitored and properly placed. As well, more accurate soil testing through zone management has created the need to address micronutrients even more. There are agronomic advantages and disadvantages of each of the following forms of micronutrients. By understanding the different types of micronutrients, you can cater the right micronutrient product to the right field and operation. Read more
Phosphorus is a nutrient that is greatly needed for high yields in crop production. It stimulates root development, increases stalk and stem strength, improves flower formation and seed production, improves crop quality, and supports development throughout the entire life cycle of the plant.
Phosphorous has also been receiving a lot of attention lately in the ag industry with the emphasis being on using the 4Rs best management practices to reduce or eliminate it moving into the Great Lakes. Many growers in the province still do not soil sample properly. If a farm is not soil sampled correctly, understanding how much phosphorous is in your soil is simply a guess. Having large quantities of phosphorus in your soil doesn’t mean it will all be available to a crop.
A plant will take in phosphorus through three different ways. In the soil including interception, mass flow and diffusion. The majority typically is taken up through diffusion which is the movement of ions from areas of high concentration to areas of low concentration. Phosphorus is very insoluble, so movement is very slow. Placement and maintaining good soil levels of phosphorus are essential. An example of this is if you have loam soil, Phosphorus must be less than ¼’’ from the root to be taken up. Phosphorus does not readily leach out of the root zone. The loss of Phosphorus mainly stems from erosion and run-off of fertiliser or soil-adsorbed P.
Many growers do not know that phosphorus can easily become tied up and unavailable in their soil.
Two important things to remember about phosphorus is:
- As the chart below indicates, high pH levels with anything above 7.3 has calcium that can combine chemically with phosphorus, making a compound that is insoluble and that crops can’t access.
- Lower soil pH that is below 6.3 can have iron and aluminium and manganese begin to tie up the phosphorus also making it unavailable to the plant, as the chart below indicates.
Phosphorus can exist in both organic and inorganic forms. In organic materials, the phosphorus is released by mineralization which occurs when microorganisms break down soil organic matter. For inorganic phosphorus, when phosphorus reacts with Iron, Aluminum and Calcium, it will create a product that is not very soluble and this is considered to be fixed or tied up.
There are several ways to protect and manage your phosphorus from becoming tied up in your soils:
- Band your Phosphorus.This keeps areas concentrated in the soil allowing less to become tied up then if it was just broadcasted on the top or broadcasted and incorporated.
- Take advantage of products that protect your Phosphorus from getting tied up. Using a product such as Avail from the Andersons can be a great option as it reduces fixation of phosphorus in the soil.
- Cold soil and starters.If organic matter is a source of P, then it will release slowly if the soil is cool and wet. Roots have a hard time absorbing P when the soil is cold. That is why starters with P close to the seed is so important.
- pH counts. We know that Phoshorus is most available between a pH of 6.5-6.8 but it can be hard to keep our soils exactly in that range. Accurate, proper, and timely soil sampling can make sure lime is being applied to correct to the pH, or acidifying products are used to lower the pH.
- Mycorrhizae to the rescue. These are fungi that live in the soil and invade plant roots. They can provide supplementary P to the plant. These fungi move out over the soil and absorb many minerals such as Phosphorus, and pass that on to the plant.
A phosphorus deficient corn plant (Purdue University).
Myths about phosphorus
- MYTH: Orthophosphate is better than polyphosphate because it is in the plant available form.
- Polyphosphate ions are readily converted to orthophosphate ions in the presence of soil moisture. If the soil temperatures are normal the conversion can be completed in days with normal soil temp. Trials done show that fertilizer applied in the different forms clearly show that a pound of P is a pound of P.
- MYTH: Liquid Phosphate is more mobile in the soil.
- Phosphate will not move very far at all in the soil regardless of fertilizer form (liquid or granular.)
- MYTH: Liquid Phosphate is available throughout the entire growing season.
- Phosphate fertilizer in any form can get tied up quickly. Only 10-30% of applied phosphate fertilizer is available during the season it was applied in. It is important to remember that seed placed P fertilizer will always be more efficiently available compared to any broadcast that is spread on the field.
- Mainly a MYTH: Elemental Sulfur acidifies the soil and frees up phosphate for the plant.
- While it is true that elemental sulfur can acidify the soil or acidify a part of the soil locally, it has not been proven to be effective for improving phosphate availability.
Several factors come into play when you are dealing with phosphorus and making it available to the plant.
Aeration and compaction
If water levels are low, absorption by roots is low.
Diffusion needs moisture, excess limits water.
P level of the soil
More P concentration to move around.
Amount and type of clay
More P concentration to move around.
Time and method of application
The longer time it is applied before a crop the more chance it has to bind with the soil. Method determines how far it will be placed from the roots.
Levels of other nutrients can affect uptake. The longer time it is applied before a crop the more chance it has to bind with the soil. Method determines how far it will be placed from the roots.
Most available at 6.5 – 6.8.
Deep rooting crops have more areas to pull from.
Temperature influences plant growth and P conversion.
Sources: mofga.org, agweb.com, Novozymes, MSU Extension, cropnutrition.com, and extension.umn.edu.
A starter fertilizer application is key to achieving the highest yield possible. It promotes an increase in early season plant growth, increased nutrient availability, and earlier crop maturity.
Applied nutrients are used more efficiently and provide a greater return on investment for your fertilizer dollars.
Finally, starter fertilizers promote good environmental stewardship because Read more
Nitrogen on winter wheat
Cereals are very responsive to nitrogen. However, over-application of nitrogen or applying too early on a thick stand of wheat can cause lodging, resulting in reduced yield, quality, and harvestability. The optimum rate of nitrogen for a particular field will depend on the type of wheat grown, past applications of manure or fertilizer, soil type, and crop rotation. Use general recommendations as a starting point but combine them with observation of crop growth and lodging tendency. The idea is to ensure nitrogen is available early and consistently though the major uptake period (which is node development though booting). Read more
Assessing winter survival in wheat Factors affecting winter survival in wheat The ability of winter wheat plants to survive winter often depends on each plant’s ability to tolerate low temperatures. Winter wheat plants go through a process called ‘cold acclimation’ in the fall during which each plant acquires the ability to withstand the cold temperatures […]
But new competitors are trying to break into the market so Canada must stay vigilant
Canada has the best identity preserved program for non-GM (genetically modified) soybeans in the world.
That’s what Neoh Soon Bin, managing director of Soon Soon Group, a Malaysian flour and oilseed-processing company, told the Canadian Global Crops Symposium here March 27.
The quality of Canadian non-GM soybeans, used mainly in human food products such as soy milk and tofu, ranks among the best in the world, Soon Bin said.
“Canadian (soy)beans perform very well,” he said.
But it’s Canada’s certification system ensuring soybeans are non-GM that really stands out. Read more
By Karen Braun
CHICAGO (Reuters) – The U.S. Department of Agriculture’s stingy forecast for domestic corn plantings could be one of the first signposts toward an increasingly bullish corn environment over the next year or so.
Industry analysts had predicted that 2018 U.S. corn plantings would fall slightly from year-ago levels to 89.42 million acres, so USDA’s peg of 88.026 million last Thursday offered a surprising jolt to the Chicago futures market. Read more
Beijing/Washington | Reuters — China quickly hit back on Wednesday at Trump administration plans to slap tariffs on US$50 billion in Chinese goods, retaliating with a list of similar duties on key U.S. imports including soybeans, planes, cars, whiskey and chemicals.
The speed with which the trade struggle between Washington and Beijing is ratcheting up — the Chinese government took less than 11 hours to respond with its own measures — led to a sharp selloff in global stock markets and commodities.
Investors are wondering whether one of the worst trade disputes in many years could now turn into a full-scale trade war between the world’s two economic superpowers. Read more