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March 10, 2010 – Oxygen an Important Plant Nutrient
The roots of most crop plants not only require moisture and plant essential nutrients, but also require sufficient air that contains oxygen. Oxygen is essential for the respiration of healthy root tissues. If excessive rain is received on a field, the lower portions of the field often have ponded water. If it persists for long, the crop will begin to turn yellow and growth is poor in these areas, compared to better drained and aerated upper slope landscape areas. The poor growth is a lack of air reaching the roots. In some areas, internal soil drainage and effective aeration can be improved by installing subsurface drainage tiles to remove excess water.
March 1, 2010 – Interpreting Nutrient Deficiencies from Plant Analysis, Consider Other Growth Reducing Factors
If there are poor growth patches in a field, one diagnostic technique is to take plant tissue samples from both good growth and poor growth areas of the field, and have them analyzed for nutrient content. I also suggest that soil samples be taken from both areas, so that you can compare both plant and soil nutrient levels to critical levels. Sometimes a plant analysis can indicate low levels of a nutrient even though soil test levels appear fine. In such a case there may be some other factor causing poor growth in the affected patches, besides nutrient availability from the soil. One example is a field of timothy grass hay I once investigated. The poor growth patches had plant tissue levels that were low in copper compared to good growth areas with adequate copper levels. A decision was made to apply a foliar nutrient spray containing copper on the field, but the poor growth areas didn’t improve. On further investigation, the good growth areas were observed to be straight-sided, geometrically shaped, and appeared to have something to do with a mechanical field operation. The field operation turned out to be an application of a broadleaf herbicide. The good growth areas were spray coverage misses where the herbicide was not applied. The timothy grass crop was sensitive to the herbicide used and physiologically the affected timothy plants were low in copper. But it had nothing to do with copper availability in the soil. This was confirmed by taking soil samples separately from the good growth and poor growth areas and comparing the soil test results. Both areas showed similar and adequate availability of copper.
February 20, 2010 – Micronutrients in Plants and Trace Elements in Livestock
Many of the micronutrients required by plants are also required in animal or human diets, even though animal and human nutritionists tend to refer to these compounds as trace elements rather than micronutrients, the term used by agronomists. Thus, livestock and humans can obtain much of their required trace elements by eating crop products or parts. Some mutually required elements are chloride, copper, iron, manganese, and zinc. There are other trace elements that are taken up by crop roots and present in plant tissues even though the crop plants can grow fine without them. This includes selenium among others. There can be situations where analysis of grain samples can indicate insufficient levels of livestock requiring trace elements, such as copper. There is a chance that fields where the grain originated is low in copper availability and applications of copper containing fertilizer could be beneficial for crop nutrition and yields, as well as for the nutrition of livestock fed the grain from these fields.
February 10, 2010 – Diagnosing Boron Deficiencies, Not an Easy Task
Boron deficiency is not easy to predict. Most soil test laboratories will analyze for boron levels in soil samples, but even if a low soil test level is the result, there may not necessarily be a crop growth or yield response to added boron. There is a greater chance to observe a boron deficiency on coarse-textured, low-organic matter containing soils in areas of higher precipitation, or under irrigation with quite pure, surface originating water. Boron is quite easily released from organic matter in soils and in some areas boron application rates are based solely on organic matter levels of soils. Boron deficiencies will be most probably observed on high boron requiring broadleaf crops such as alfalfa, sugar beet, and canola. Even though boron is mobile in soils, it is slowly mobile in plants and if there is a boron deficiency it will most affect the younger and growing point portions of crops. It is quite dramatic in alfalfa where the alfalfa plants are stunted with tips of the top of the plants having small leaves that are yellow in color; this is called “yellow-top” of alfalfa. In canola, the plants are stunted in height, have poor flower bud formation, and the small flowers formed tend to be misshaped and pale in color compared to boron sufficient plants that have larger deep yellow-colored flowers. If a boron deficiency is diagnosed early enough in the crop season a top-dress application of a low rate of boron in a foliar fertilizer may help restore yield potential.
February 1, 2010 – Know the Carbon to Nitrogen Ratios of the Manure You Add to Your Fields
It is always good for crops if you add manure to fields, right? Well, not always. I was working in north-central British Columbia about 10 years ago and was asked to visit some fields of barley that were doing poorly. The grower said that he had applied lots of manure to the fields, but the barley looked stunted and pale yellow. It was classic N deficiency. I asked what the source of manure was. It was feedlot manure from a neighbor’s feedlot. It turned out the bedding material in that area was saw dust originating from sawmills in the area. Price of sawdust was very reasonable and the steers in the feedlot were bedded very well. The sawdust was primarily from the lumbering of spruce or pine, and had little N compared to the carbon in the original wood. Generally this type of sawdust has a C:N ratio of 400:1 compared to well rotted manure that can have a C:N ratio of 20:1. Usually, any organic material having a 20:1 or less C:N ratio will result in a net release of N when applied to a soil. From a 20:1 to 30:1 C:N ratio net mineralization is close to zero. Materials having a C:N ratio greater that 30:1 tend to tie-up soil N. The 400:1 C:N ratio material used on the barley fields severely tied-up N. I suggested that adequate supplemental N in the form of urea be added to any fields that would receive the sawdust containing manure in the future. The correct amount of N can be calculated if the manure being used is sampled and analyzed for C and N content, and the actual C:N ratio is determined.
January 20, 2010 – Chloride and Plant Nutrition
One of the fourteen mineral nutrients required by plants is chloride. The chloride ion (Cl-) occurs naturally in the environment, deposited on soil surfaces in low concentrations with precipitation. The closer land is to the ocean the higher the concentration of Cl- in the rain. The interior of continents, e.g. the Northern Great Plains of North America, receive lower levels of Cl- in rain, and under certain soil conditions the amount available is less than needed by plants. To supply Cl-one of the most widely used sources is potassium chloride (KCl), commonly called muriate of potash. Muriate of potash fertilizer is usually used as a source of K fertilizer but is an excellent source for Cl-also. When having soil samples from crop fields analyzed for plant available nutrients, it can be useful to request the test for Cl- besides the usual nutrients of N, P, K, and S. The Cl- test is often included in a soil test package including micronutrient analysis. It has been observed that a soil can have adequate supplies of K, but be low in Cl-. The small grain cereal crops, specifically wheat and barley, tend to require more Cl- than broadleaf crops such as oilseeds or pulses.
January 10, 2010 – Where Does the N in Nitrogen Fertilizers Come From?
Most common N containing fertilizers, for example urea, anhydrous ammonia, urea-ammonium nitrate solution, ammonium nitrate, etc are manufactured from N that originated from the air. The air we breathe contains about 78% N in the form of di-nitrogen gas (N2). This gas is rather inert and needs to be converted over to a form of N that can react and be used to form life-sustaining compounds that have N as part of the molecular composition, for example proteins. We commonly call the conversion of N from the inert N2 gas to a reactive form as “Nitrogen Fixation”. The ammonium ion (NH4+) is a common reactive N form first produced biologically by bacteria in the soil, e.g. Rhizobia sp., or Azotobacter sp. Industrially fixed ammonia (NH3) is manufactured by using the so-called Haber-Bosch process. This NH3 forms NH4+ when reacted with water. The fixation of N does require considerable energy whether it occurs biologically, or industrially. Most manufactured N fertilizers are presently made using natural gas (CH4) as the energy source. This is why N fertilizer prices are usually closely tied to natural gas prices.
January 1, 2010 – Aluminum Toxicity
Crops grown on acidic soils can be adversely affected by aluminum toxicity. At these low soil pH values (<5.0 -5.5), aluminum is present in soil solution as the Al3+ ion. This ion interferes with cell division and restricts root growth especially affecting root hairs where most of the absorption of plant nutrients occurs. There are a few ways to reduce the effects of aluminum toxicity, one is to apply and mix in a finely-ground lime source to a field’s soil and raise the soil pH above the 5.5 level, ideally to a pH value between 6.5 and 7.0. Another way is to grow crop varieties that are more tolerant of aluminum. For example wheat varieties can be selected and grown that are more tolerant of aluminum that other wheat varieties. Lastly, grow crop species that better tolerate aluminum.
December 20, 2009 – Don’t let logistics restrict you from adjusting fertilizer rates and methods for each field or part of a field.
Sometimes, just fertilizing the way you normally do may not give you the improved yields and increased net incomes you want. For example, on some large farms a specific fertilizer blend, rate, and application method is used for each field of a specific crop type… one fertilizer method, blend, and rate for wheat, another for barley, and a third for a pulse crop. This makes logistics easier especially if there is a large area of cropped land to cover, and if the available labor pool is not well experienced. However, being able to accommodate specific fertilizer rates separately for each field or a portion of a field can allow increased fertilizer use efficiency, and result in improved net incomes. The first step may be to treat each field separately, and the extreme step is to treat parts of a field separately and variably rate apply fertilizer within a field. Equipment and technology to accomplish variable rate fertilizer within a field is becoming more possible, practical, and economically viable. Check for variable rate farm groups, farmers, or consultants in your local area and see if it may fit in your future farm plans.
December 10, 2009 – Ask for a second opinion when interpreting your soil test results and developing a fertilizer recommendation.
There are different approaches to making a fertilizer recommendation and it can be useful to obtain a second and third opinion, other than your regular source. For example, rather than just use the recommendation that comes along with the soil test report from the soil test lab you regularly use, also ask for a recommendation from a local crop consultant, and put your soil test results into a recommendation software program developed for your state or province. (These are often available on state or provincial ag-extension websites.) If one of the sources is radically different from the other two, ask someone representing that system how the recommendation is developed and why it would be so much different from the other two systems. You might gain some information on how to improve your fertilizer recommendation and this may result in improved crop yields and net income.
December 1, 2009 – Where do errors in soil sampling and analysis originate?
Soil test laboratories can make mistakes in analysis, but the reality is that this is rare because of regular practices of running check or standard samples along with each batch of new soil samples analyzed. If the check sample values are too far off, the lab will make adjustments, check equipment and chemical solutions, and repeat the analyses until check sample values are within acceptable normal variability around a previously accepted level. If soil test results are unusual it is most often because of mistakes made when sampling in the field (e.g. sampling an area where there was an old manure pile years ago), or some type of contamination or mishandling of samples before they arrive at the soil test lab (e.g. left in a warm area for a couple of days before submitting to the lab and more N is mineralized than normal).
November 20, 2009 – What to do if your soil test results look out of the ordinary.
It is most useful to keep records of soil test results previously done on a field and compare those results to the one you have done this cropping year. If a certain test is noticeably different from previous years, it is good to try to understand why, and whether or not this is something to be concerned about. In some cases, this difference may be due to out of the ordinary weather conditions. For example, after a year of extreme drought, residual N levels will probably be higher than normal. Conversely, after a year of greater than average rains and better than normal crop growth, residual N levels may be lower than normal. You may want to adjust your fertilizer rates down or up appropriately.
November 10, 2009 – Don’t be timid about asking questions about your soil test results.
There is nothing wrong with asking questions about soil test results. If you don’t understand what a specific test result means, ask for an explanation. You will learn something about your soils, and how you might manage your fertilizer or soil amendment applications better.
November 1, 2009 – How does the laboratory you use to have your soil test analyses done compare to other laboratories?
Chances are, probably quite well. However, if you are interested in comparing results, next time you take soil samples mix the samples well, and send sub-samples of the same sample to two other laboratories you don’t regularly do business with, as well as your regular laboratory. Normally, the test results will come back very similar. If the soil test levels of specific nutrients are noticeably different it may be that the labs use different methods of sample preparation, extraction, and analysis. It may be useful to ask the different lab agronomists, an extension service soil specialist, or your crop consultant why one analysis type may be better suited, or not, for the soil types on your farm.
October 20, 2009 – Don’t cheat on the number of cores when obtaining a composite soil sample from a field.
It has been proven that between 15 to 20 soil cores should be randomly taken from representative areas of a field, mixed together, and a sub-sample taken and sent to a soil-test laboratory for analysis, to accurately estimate the nutrient status of a field. Taking fewer cores can result in a less than accurate estimate, and taking more cores may unnecessarily take more time than needed.
October 10, 2009 – How often should you have soil samples taken and analyzed from each of your cropped fields?
Ideally yearly, but because of time constraints, weather interruptions, and perceived excessive costs most fields do not have soil samples taken and analyzed yearly. It is advised that samples be taken at least every 3 years to monitor levels of plant available nutrients and determine if the nutrient status of the soil is being maintained to produce the desired crop yields.
October 1, 2009 – Assessing your plant nutrient account after harvest – “Nutrients In, Nutrients Out and the Nutrient Balance”.
Account statements are done routinely for our financial savings and checking accounts. The statement lets us understand money in, money out, and what the balance is. One way to evaluate how well your fertilizer program worked this past growing season is to conduct a similar process or a so called “Nutrient Account Balance”. In general terms, this can be done as follows:
- Nutrients added is equal to fertilizer added, on a lb/A (kg/ha) basis. (Nutrients In)
- Nutrients removed are calculated by multiplying removed harvest yields by standard or analyzed nutrient concentrations per unit of yield. In this way the amount of N, P, K, and other nutrients removed or withdrawn from a field can be estimated. (Nutrients Out)
- Ideally Nutrients In = Nutrients Out for a crop-soil system to be maintained at a productive level. If nutrient applications have been less than removal the Nutrient Balance will decrease, and conversely if nutrient applications have been excessive the Nutrient Balance will increase.
- The Nutrient Balance can be estimated for some nutrients, especially N, by having soil samples taken yearly and analyzed for plant available levels. If levels of availability are higher than normal, then chances are Nutrients In exceeded Nutrients Out. Conversely, if levels are lower than normal, fertilizer rates may have been less than required for the desired Nutrient Balance.
September 20, 2009 – Conduct a nutrient accounting exercise on some of your fields after harvest.
Just as persons routinely read over bank statements to see how their checking and savings accounts balances are doing because of dollars in and dollars out in a month, it can be beneficial to do a simple accounting exercise on some or even all your fields for the cropping year. You don’t look at dollars into and out of the field, but you check to see how nutrients in and nutrients out compare. For example on a field where you planted winter wheat you may have applied the following nutrients, 110 lb N, 20 lb P2O5, 10 lb K20, and 10 lb S per acre. The wheat crop yielded 75 bu/A of grain at 12% protein. This equals about 95 lb N, 38 lb P2O5, 26 lb K2O, and 11 lb S in the grain only. Since the grain is sold off the farm it would appear that sufficient, or perhaps an extra 10 lb N was applied but there was a deficit of 18 lb P2O5, 16 lb K2O, and 1 lb of S. You may want to consider applying more P, K and S fertilizer on that field in future years to better maintain the nutrient status of the soils in the field.
September 10, 2009 – Avoiding fertilizer blends that are subject to absorbing excess moisture over the winter.
A blend of N, P, K and S fertilizers can be more susceptible to absorbing moisture from humid air and become lumpy, than the unblended fertilizers that are used to make the blend. For this reason some farmers choose to store separately their fall or winter purchased fertilizers, as original non-mixed fertilizers, then have them blended in the spring, just before application. In the more arid or low humidity areas, this is less of a potential problem. It is useful to ask the advice of your local fertilizer retailer to determine if fall blending and storage is a risk you should avoid or don’t need to worry about.
September 1, 2009 – Is it a good economic practice to purchase fertilizer in the fall rather than wait until the following spring?
Farmers have the option of purchasing their fertilizer in the fall, or the following spring for next year’s crop. If fertilizer prices are lower in the fall compared to the following spring this can mean savings to the farm operation. Many farm operations routinely buy their fertilizer in the fall. In the fall of 2008 compared to the spring of 2009 this was not the case as the result of world market conditions. However the majority of the time fall prices are lower than the corresponding next spring prices. For this reason overall risk can be reduced if fall purchases are chosen.
August 20, 2009 – fall soil sampling is a good strategy for the majority of the Northern Great Plains.
In some of the more humid farming areas of North America fall soil sampling done to test for soil nitrate is not routinely used to assess N nutrient availability for the following year’s crop because whatever soil nitrate is present at the time of sampling is usually leached or denitrified out of the soil before the following spring. For this reason, soil sampling in the spring before planting is preferred. However, in the more arid west, fall soil sampling has proven to be a reliable source of information to help predict N availability for the next year’s crop. The advantage of using fall soil sampling is that it allows more time to formulate fertilizer recommendations before the busy spring planting season.
August 10, 2009 – Intensive livestock operations can be a valuable source of crop nutrients if the nutrients are used effectively but not in excess.
Taking soil samples on fields surrounding and part of an intensive livestock operation is an important starting point for development of a nutrient management plan for such an operation. In some states and provinces the legislation requiring nutrient management plans has only come into effect over the past decade and in others it is forthcoming. Either way a nutrient management plan can be very beneficial to the operation whether required by legislation or just because of environmental, economic or agronomic motivation. Manure is a valuable source of plant nutrients and should be considered a resource not something just to be disposed of. In many cases, especially if the livestock operation is quite large and has been spreading the manure for a number of years on a limited land base, the soil sampling results will indicate that continued applications of manure is leading to excess loading of the soil with plant nutrients. In such instances it is important for the management of the operation to discuss with owners of adjacent land that has not previously received manure about the possibility of them receiving manure onto some of their fields. Such cooperative arrangements are mutually beneficial to both the livestock operation and the surrounding farms that do not have livestock. The livestock operation can avoid excess nutrient loading on its fields, and the non-livestock operation can utilize the nutrients in the manure to help satisfy crop needs.
August 1, 2009 – Certain crops will grow better when grown in a certain order within a crop rotation, why?
Sometimes the reason a specific crop will grow better after one crop type compared to another is that there may be crop disease organisms that can infect some crops, but not infect others. For example many broadleaf crops are susceptible to a Schlerotinia sp. infection but cereal crops are not. So by having both broadleaf and cereal crops in your rotation you can reduce the potential for Schlerotinia in your broadleaf crops. It is useful to contact your local crop disease specialist to determine whether or not your present crop rotation is helping you mange the incidence of crop diseases in your area.
July 20, 2009 – Threshold level guidelines are useful to help you decide whether or not to apply a foliar fungicide.
If weather conditions are favorable to encourage foliar fungal growth it is useful to scout your crop and determine whether or not a leaf crop disease is present. Most fungicide products come with information on how to assess the extent of disease infection at various crop stages. The term threshold level is used and is based on what percentage of the crop leaves are covered with fungal infections. For example, if infection is over a specific amount, e.g. 30%, then application of a fungicide may be beneficial. The exact threshold levels for different foliar diseases have been researched, and determined. You should be able to obtain that information from you local crop adviser or a plant control product sales representative.
July 10, 2009 – Plant analysis is a tool to help determine the nutrient status of a crop, but often you need other information to really understand what is going on, be cautious in the interpretation of results.
Sometimes if you only rely on a plant analysis result you might be mislead. This is because laboratory analysis results only tell you the content of the plant nutrients in the plant tissue sampled, and don’t tell you the soil conditions, the weather conditions, nor any field history. All of these other factors can help you know why plant nutrient contents may be adequate, higher, or lower than normal sufficiency levels. For example wheat plants taken from a poor growth area may show adequate levels of most nutrients but the reality is that because of excess salinity in the soil the crop will never grow well and yield well. It is always useful to take a soil sample from the same area where the plant tissue samples are taken. Also take note of the past and present weather conditions and other fertilizer and herbicide applications that might have affected crop growth.
July 1, 2009 – Take time to observe crop growth in your fields
It is worth your time to see how well crops are growing in your various fields. Often you will be pleased to see that everything is fine and that the crops are growing well. However sometimes you will discover some patches of poor growth. You then have the opportunity to observe what the poor growth symptoms are and try to diagnose the cause of the poor growth. In some cases you may discover a pest infestation early when the poor growth area is small, and if a pest control application of a fungicide or insecticide is needed you have time to apply it before the small poor growth area becomes a large poor growth area.
June 20, 2009 – Early Weed Control Is Better Compared to Delayed Weed Control
Another benefit of scouting your fields early is to ascertain what weed species are present and in what numbers. This can help you decide if and what in-crop herbicide weed control you may want to use. By applying herbicides at the correct stage of the crop and at an early stage of the weed seedlings, the effectiveness of the herbicide can be optimized. Delayed weed control can often result in reduced weed control and reduced crop yields.
June 10, 2009 – Scout Your Fields Early for Poor Growth Areas
While scouting your fields soon after emergence, it is worthwhile taking note of areas of poor growth compared to the field average. The hindered growth may be due to one of many possible effects. It might result from an insect or disease infestation, a patch of micronutrient deficiency, an area of different soil pH allowing a soil residual herbicide from a previous year’s application to limit growth, or in some cases a shallow sand lens in a field showing up as more drought-prone in a dry year. Sometimes you can tell quickly and easily what the problem is (i.e. an infestation of cutworms), or it may be more complex and require some soil and plant samples to be taken and analyzed (i.e. a micronutrient deficiency). If you have the services of a crop consultant or certified crop adviser available, they can come and look at the area at your request. You may want to take note where the poor growth area is by recording the location using a handheld global positioning system (GPS) unit. This is called recording a “Way Point” in the GPS unit. It is much easier to return to the exact spot later than trying to find the way back by memory alone.
June 1, 2009 – Monitor Your Emerging Crops for Insect Pests
It is unfortunate to do an excellent job of planting and fertilization and then suffer severe crop damage from insect pests, especially in the early seedling stages of the crop. It is worthwhile being aware of potential insect pests in your area. Most state or provincial agriculture websites contain insect pest forecasts, usually displayed as a map. You can see if the potential for different insect pests is high in your area and scout your fields as your crops begin to emerge and become established. If insects such as cutworms or grasshoppers are noticed early enough and the infestation level warrants an insecticide application, it is often possible to protect the crop and suffer little yield loss. Early detection is the beginning step for a successful in-crop pest control program.
May 20, 2009 – When Side-Banding Your Fertilizer Blend, Make Sure You Have Adequate Separation between the Seed-Row and the Fertilizer Band
The practice of side-banding all the required growing season fertilizer, relative to the seed-row, during the planting operation is commonly called “double-shoot one-pass seeding”. This has been shown to be an effective way to apply fertilizer for small grain cereals and canola in the drier areas of the Northern Great Plains. Care must be taken, however, to make sure there is sufficient separation between the seed and the fertilizer band. This separation can vary depending on the soil texture and moisture conditions. For example a 1.5 in. (3 cm) separation may be sufficient for a 90 lb N/A (100 kg N/ha) rate for wheat on a moderately moist clay loam textured soil, but 2.5 in. may be required if seeding the same crop on a somewhat dry sandy loam textured soil.
May 10, 2009 – Sometimes Increasing Your Planting Speed to Finish Sooner Can Cause More Problems than Benefits
Sometimes in an effort to speed up planting, especially in a crop year with a late spring, or a planting time interrupted by excessive and or untimely rains, a grower may increase tractor speed to finish planting sooner. However, a planting speed that is too fast can result in poor seed placement. The goal of planting is to have the seed placed at the proper depth, with good soil to seed contact, and adequately packed to facilitate seed absorption of soil moisture. Most planting equipment is designed to work effectively at a ground speed of 4 to 5 mph (6 to 8 km per hr). The main adverse effect of excess planting speeds is that the average seed depth variability is increased dramatically. Some seed is placed too shallow as soil and seed is thrown out of the seed furrow, and the same soil can land on seed furrows of rows planted by openers in the forward ranks of the planter, resulting in too deeply-placed seed. The result is uneven emergance that can have less than optimum plant stands, and/or uneven crop ripening and maturity. Check the recommended planting speeds for your planter and soil opener design. Staying within the recommended speed range can help obtain a more even and faster emerging plant stand.
May 1, 2009 – A Seed-Row Starter Fertilizer Can Help Get Your Crop Off to an Excellent Start
The benefit of a seed-row starter fertilizer is that your crop can have access to adequate supplies of required nutrients sooner and will grow faster and with more vigor than if no seed-row starter was used. Such blends usually contain a combination of N, P, and K, plus other nutrients as specific regional soils and fields require. Most are usually P dominant as this nutrient is especially beneficial in aiding seedlings to grow quickly. However, care should be taken not to apply excess rates of the starter that can result in reduced plant stands and vigor due to potential ammonia toxicity from excess ammonium based N in the fertilizer blend, or salt damage from the salt-moisture-osmotic effects of mineral fertilizers. Consult your local crop adviser for recommendations specific to your crops grown, and local soils and climate conditions.
April 20, 2009 – Use a Planting Rate Calculator Formula to Help Ensure an Adequate Plant Stand
Achieving an adequate plant stand has numerous benefits. It helps your crop compete with and suppress weed growth, makes better use of available moisture, nutrients, and sunlight, and helps to produce an earlier and more even maturing crop. The ideal plant stand for each of the crops you grow can be looked up in crop specific growing guides available from state, provincial, or crop specific grower groups. For example, most spring wheat does well at a plant stand of 20 to 25 plants per sq. ft. (215 to 270 plants per sw. m). Each batch of seed even within a specific variety can have some differences in seed size, seed weight, and percent germination. For that reason, a seeding rate calculator is useful to determine the rate of seed your planter should be set at, to achieve the desired plant stand. You can check with your local extension service to find a formula used for your specific crop. An example of one used for spring wheat is shown below.
Seeding rate (lb. per acre) = target plants per sq. ft x TKW (thousand kernel weight in grams) x 10 (a conversion factor) ÷ percent germination
If the target plant stand is 25 per sq. ft, the TKW is 30 g, and percent germination is 90, then the seeding rate is as follows:
Seeding rate = 25 x 30 x 10 ÷ 90; or 83 lb/A
April 10, 2009 – Plan Your Spring Planting with the Goal of Seeding at the Optimum Time for Each Crop
One of the benefits to having a well planned rotation is that it helps you spread out your planting operations. Most spring-seeded crops have an ideal planting window for your region and if you can plant that specific crop within those calendar dates you increase your chance of obtaining the highest possible yield. For example, a farmer may grow field peas, spring wheat, canola, and barley in a 4-year rotation. By starting planting early with the field pea crop, best suited to early planting, it leaves more time to plant the other crops. The next crop may be the spring wheat that does well when planted early and takes more days to grow and mature than the barley crop. Canola may need to be planted third as it is less tolerant of late spring frosts than the peas and wheat, and the small seed size makes it less tolerant of setting in cool soils if spring temperatures are cooler than normal. The last seeded crop may be barley, not that barley can’t be seeded earlier, but it generally takes fewer days to grow and mature and planting a bit later does not adversely affect potential yield as much, and it has a better chance of reaching maturity before fall frosts compared to the other three crops. The main factors to consider when planning the order of seeding crops is tolerance to cool soils, late spring frosts, and required days from emergence to maturity.
April 1, 2009 – Quality Seed Grain Is the First Step in Growing a High Yielding Crop
There are many important management decisions that go into growing a high yielding crop. The first step is to begin by planting seed that is of good quality. Poor quality seed can result in reduced plant stands and slow establishment, be less competitive with weeds, and not grow and yield as well as healthy strong seed. You should try to have seed that has high germination, strong vigor, is pure in content (or has very low levels of off-types or weed seeds), and was grown on a field that had adequate crop nutrition applied, and good harvest conditions. The germinating seed and young seedling derives the initial nutrients for growth from the energy and elements stored in the seed itself. If you are purchasing seed grain, or having your own grain cleaned for seeding, it is beneficial to have the grain tested for purity, germination, seedling vigor and presence of seed-borne diseases. You may pay a bit more for high quality seed, but it pays back by giving you strong seedlings, an adequate crop stand, and a vital first step towards the crop you want.
March 20, 2009 – How Viable Is It to Use Rock Phosphate Compared to an Ammonium Phosphate Fertilizer Source
I was recently contacted by a farmer who asked whether or not rock phosphate was a viable alternative to using monoammonium phosphate (MAP or 11-52-0). He had a neighbor who could back-haul granulated rock phosphate to his farm for a price less than half that of MAP. The prices at that time were respectively $500 and $1,150 per metric ton (1,000 kg or 2,205 lbs). The comparison of the two products is shown below in Table 1.
| Table 1. Comparison of granulated rock phosphate and MAP on cost per pound of available P2O5. |
Product | Total P2O5 content | Availability* of P in the product | Available* P2O5 content | Cost $/T | Cost, $/lb total P2O5 | Cost, $/lb available P2O5 |
Granulated rock phosphate | 27% | 22% | 6% | $500 | $0.84 | $3.79 |
MAP | 52% | 100% | 52% | $1,150 | $1.00 | $1.00 |
| *Water soluble plus citrate soluble. |
Rock phosphate does contain P, but it is in a form that is less soluble and less available to crops than a soluble processed material such as granular MAP. MAP is produced when ground rock phosphate is treated with sulfuric acid and the soluble phosphoric acid produced is reacted with ammonia to produce the MAP. On a cost per pound of soluble P2O5 the rock phosphate was three-times the cost of the MAP.
March 10, 2009 – Don’t Forget the Benefits of Rotating Crops in Your Cropping System
Sometimes when certain crops increase in price and others decrease in price a grower may want to grow the same crop back to back, or even for several years in a row. This is in contrast to a regular crop rotation previously used. The monoculture of a specific crop with no alternate crop or crops in rotation can be very risky for some crops and rarely beneficial for any crops compared to rotating different crops. For example, it has been advised for many years to grow canola only once in every 4 years because of the build-up of fungal diseases such as sclerotinia and black leg. However, when canola prices over the past decade were higher relative to cereal crop prices, many growers shortened their rotations to have canola grown once every 3 years, once every 2 years, or in some cases every year for a few years in a row. Recently reported research has shown that with newer disease-resistant canola varieties, it is possible to grow canola as often as once every 3 years, but once every 2 years or back to back usually results in great enough yield decreases that a more extended rotation is preferred as far as net returns. If you are considering shortening your crop rotations it is advised that you speak with a local crop extension specialist to determine how great your risk is for severely lower crop yields.
March 1, 2009 – Why Has No-Till Cropping Use Increased in the Northern Great Plains?
The main reasons have been decreased fuel usage, less required farm labor, and reduced time required to plant fields for no-till systems. The other significant benefits have been reduced wind and water erosion, and better conservation of soil moisture. It is observable that there is more no-till compared to reduced till in the more arid areas, and often the reverse in the more moist regions. For example, in the arid regions of Montana, Alberta, Saskatchewan, and North Dakota, no-tillage is used on as high as 80% or more of cropped dry-land acres. In the more moist areas such as the Red River valley in North Dakota and Manitoba no-tillage is used on less than 10% of the cropped acres. The same low no-tillage use is observed on irrigated lands in the arid portions. However, in both the arid and more moist areas, the use of intense inversion tillage that buries all crop residues is rarely used. The use of reduced tillage that retains at least a portion (e.g. 25%) of the previous crops residue on the soil surface is common even in the moister areas.
February 20, 2009 – Planning Your Fertilizer Applications in a Year of Changing Prices
Over the past year there was a great increase in grain prices and fertilizer prices followed by monetary market instability that has caused a decrease in grain and fertilizer prices. These changes make it challenging to accurately estimate what net returns will be for crops to be grown next year. However, growers will always do better economically by growing a relatively higher yielding crop with available resources. In crop production, you rarely “save yourself into prosperity” by purposely growing a low-yielding crop.
February 10, 2009 – Crop Uptake and Nutrient Use Efficiency
Often the amount of uptake of a nutrient in the year of application into a crop can seem quite low. For example, crop uptake in the year of application for N and P can be 45% and 15%, respectively. Usually, very little of the remaining portions of the applied nutrients are lost and most remain residual in the soil and become available to subsequent crops. For example, under cropping conditions in the Northern Great Plains, the eventual uptake of applied nutrients can be over 90%. For N, this may occur within a few years, while for P this may take up to a decade or more. It is important to realize there are a few different potential pools of available N and P in the soil and portions of the N and P used by a crop in any one year comes from these different pools along with the fertilizer source. In general terms, the different pools of residual and stored nutrients are as follow:
- Inorganic N and P dissolved in the soil water solution.
- Inorganic N (NH4+) and P loosely adsorbed onto the surfaces of soil mineral and soil organic matter particles.
- Inorganic N (NH4+) and P tightly reacted with and bound to soil particles and or precipitated with other ionic forms of compounds. For example, phosphate reacting with calcium or magnesium ions to form low solubility compounds, and
- Organic forms of N and P in soil biomass (crop tissues, crop residues, soil organisms, and soil organic matter).
February 1, 2009 – Statistical Analysis Is a Necessary Tool in Research
The statistical analysis of research results evaluating new fertilizer products is extremely valuable when deciding whether or not a new technology is better, equal to, or not as good as existing practices. When you are shown research results and the average crop yield using a new product is greater than the average yield using an existing product, then there should be mention of the statistical difference between the yield averages of new product and the existing product. If it isn’t shown or mentioned, it is your right as a potential customer to ask if the statistical analysis results are available. If these are not immediately available, ask if the results could be forwarded to you. In scientific research, verbal claims of superior effectiveness are not considered valid unless backed up by sound statistical results.
January 20, 2009 – New Fertilizer Products
Suppose you are at an agricultural crop show this winter and see a display announcing the release of a new fertilizer product that sounds promising. How do you know if it will work well for your farm’s soil and cropping conditions? If a company marketing a new fertilizer product has done adequate research and development they should have independent research results available to show that the product is effective. Sometimes the product may have performed well in research trials and field tests in an area quite far geographically from your farm. In this case you may ask if they plan to commission third-party research trials nearer to your area. If the product sounds like it may be a useful addition to your farm you may want to offer to have a small research trial on your farm conducted by a local applied research association or state or provincial extension specialist. It is most useful to have research results from “your own backyard” so to speak when considering new products.
January 10, 2009 – Field Records are Valuable When Making Management Decisions
Recording information about specific fields such as crops grown, soil sampling analysis results, fertilizers and herbicides applied, and weed, insect and crop diseases present, are valuable when making cropping decisions. For example, if a grower wants to grow a crop that is a weak competitor with specific weeds and those weeds have been a continuing problem on a field, it may be better to grow that crop on a field where those weeds are not present or occur at low population densities. Information from field records can help avoid problems, or in some cases allow applications of specific fertilizer nutrients to correct nutrient deficiencies, or the right fungicide applications to control certain fungal diseases.
January 1, 2009 – Treat Animal Manures as a Fertilizer Resource
It is important to make good use of plant nutrients whether they come from the soil, fertilizer, or livestock manure. Manure is too often considered a material to be disposed of, rather than a valuable source of plant nutrients. It is amazing how valuable a load of manure can be if you had to supply the N, P, K, and S by purchasing fertilizers. For example, a ton (2000 lb or 907 kg) of feedlot manure that had some straw bedding material can contain about 20 lb N, 7 lb P2O5, 14 lb K2O, and 5 lb S. If the prices per pound of N, P2O5, K2O, and S were respectively $0.60, $0.70, $0.40, and $0.70, the value of a ton of feedlot manure would be close to $26. If the manure were applied to a field at 10 tons of manure per acre this could represent about $260/A of plant nutrient value…and that ignores its organic matter and micronutrient contributions.
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