Production Pointers - Dr. Mike Stewart

June 20, 2014 – Plan winter wheat fertility programs now
Now is the time to start planning your winter wheat fertility program. Take soil samples early, while time allows and before other duties take priority. Fertility management for wheat produced for grain versus forage and grain will differ. Remember, regardless of whether wheat is to be used as a dual crop or for grain only, adequate P nutrition is critical to the production of optimum yields.

June 10, 2014 – Mid season foliar K on cotton
If midseason foliar K applications to cotton are planned this season remember that solution pH affects uptake and performance. Research has shown that common foliar K sources perform best when solution pH is buffered to levels between 4 and 6.

June 1, 2014 – Maintain adequate K for bermudagrass
Split applications of N are common in hybrid bermudagrass hay production. Growers often apply N after each cutting to optimize productivity and improve N use efficiency. Although not as common, splitting applications of K under some conditions may also be advantageous. Bermudagrass requires and removes large quantities of K so maintaining adequate available K levels throughout the season is important. In sandy soils K is subject to leaching, so multiple applications can provide more consistent season long fertility, especially in high rainfall areas.

May 20, 2014 – Bermudagrass nutrient removal
Hybrid bermudagrass has tremendous yield potential. An important factor in realizing that potential is complete and balanced fertility. When planning bermudagrass fertilization programs this season keep in mind that each ton of bermudagrass hay removes about 46 lb N, 12 lb P₂O₅, and 50 lb K₂O.

May 10, 2014 – P and K on alfalfa
Alfalfa is a high quality forage crop with high yield potential. Phosphorus and K fertility are important factors affecting alfalfa production. When planning alfalfa fertilization programs this season, keep in mind that each ton of alfalfa hay removes about 15 lb P₂O₅ and 60 lb K₂O.

May 1, 2014 – K in cotton production
Potassium is an extremely important nutrient in cotton production. Bolls are major sinks for K. Thus, the need for K increases dramatically during early boll set. About 70 percent of uptake occurs after first bloom, and uptake peaks at about 3 to 4 lb K₂O/A/day. Potassium deficiency may be expressed as a full season deficiency, or it may not appear until late season during the period of greatest demand. When a heavy boll load is set, the demand for K may exceed the ability of the soil and leaves to supply it, resulting in a late season deficiency. Mid-season foliar K fertilization can be effective in correcting late season deficiencies.

April 20, 2014 – Fertigation
Fertigation can be a good way of splitting nutrient applications during the season. If fertigation is an option, consider what nutrients and quantities will be applied through the irrigation system. Consider using a “jar test” well in advance of application to test the compatibility of your water with fertilizer. Compatibility testing prior to application is especially important if P fertigation is planned. Adjusting rates and sources of nutrients can eliminate problems of compatibility between fertilizer and irrigation water. Simple precautions can prevent clogging and fouling of irrigation systems that results in lost time and profit.

April 10, 2014 – Balanced fertility and N use efficiency
Nitrogen use efficiency has long been a topic of considerable interest. One of the most important things that can increase N use efficiency is to make sure that complete and balanced fertility is in place. For example, high-yield irrigated corn research in Kansas has shown that balancing N, P, K and S increased apparent N recovery from 33 to 75% compared to the N only application. So, to get the most out of every unit of N make sure the need for other nutrients is addressed.

April 1, 2014 – Balanced fertility and water use efficiency
Water use efficiency is an important factor in crop production, especially in periods of drought or in areas with limited irrigation capacity. A balanced fertility program helps maximize water use efficiency since it enables greater production per inch of available water.

March 20, 2014 – Avoid compaction during planting
Remember when preparing to plant this spring that entering fields that are too wet leads to serious compaction. Compacted soils are problem soils. Problems created may include: water run off rather than infiltration; nutrient uptake efficiency is reduced; germination is uneven resulting in poor stands; and root growth is restricted.

March 10, 2014 – Manure and nutrients
Unlike commercial fertilizers, the nutrient content in manure can vary dramatically. Because of this variability, it is important to sample and test manure to ensure that you know the nutrient rates being applied. The other aspect one should be aware of in managing manure is the portion of nutrients that are immediately available, versus that which will be released over time. For example, 50 to 90% of the P in manure can be in the organic form and require some time before it is released and becomes plant available. Understanding the dynamics of manure nutrient content and availability is critical to maximizing crop production where it is used.

March 1, 2014 – Consider broadcast and band applications
Banded nutrient applications generally provide higher first-year recovery of applied P and K than do broadcast applications. If short-term economic decisions dictate banding P and K at rates less than those of crop removal, producers and advisers may want to build in a plan for replenishing soil nutrient supplies in the future. In fields with longer-term management strategies, a combination of a banded application with a broadcast application may be best. Bands placed near the seed provide early season access to nutrients, while overall higher fertility levels in the bulk soil provides access to nutrients by the whole root system later in the season.

February 20, 2014 – Balance N, P, and K inputs
Balancing nitrogen (N) fertilization with adequate P and K is a proven Best Management Practice. For example, with adequate P response to N is improved, maturity is hastened, and yields are increased. Improved root growth with adequate P can also enhance the capture of soil and fertilizer N, thereby increasing N recovery efficiency.

February 10, 2014 – Nutrient removal may vary
An accurate accounting of crop removal of P and K is an important component of a nutrient management plan. Measurements of removal indicate that P and K contents of harvested corn grain vary considerably across sites and growing conditions. When estimating what your crop removes, you may want to consider getting your own specific analysis.

February 1, 2014 – Starter bands
Starters benefit corn in cool, moist soils. Nitrogen and P work together to boost the vigor of the young seedling, and K and S can be important in some soils. In calcareous soils (high pH) starters can also improve the root environment by temporarily lowering pH. Ammonium forms of N and mono-ammonium phosphate are particularly good acidifiers. The small band of soil with lowered pH can supply more manganese, zinc, iron and P while the seedling is still young.

January 20, 2014 – Consider nutrient removal and use
Now’s a good time to evaluate the nutrient balance from last year’s harvest. Balancing the financial books is always a good idea, so why not check the balance (removal vs use) on the nutrients in your fields? You can calculate how much P and K your crops removed by multiplying last year’s yield by the amount removed per unit of production (bu, bale, etc.). You can find those figures at the IPNI website or in most soil fertility handbooks.

January 10, 2014 – Consider chloride on wheat
Winter wheat has been shown to be responsive to topdress application of chloride (Cl) under certain conditions. On average, in responsive situations, winter wheat has shown about 5 bu/A response to Cl. Topdress application rates usually vary from 20 to 40 lb Cl/A, and can be made in combination with N topdress application. Factors favoring response are low soil Cl level (<30 lb Cl/A- 2 ft depth), low tissue Cl level (<0.4% Cl), and/or high foliar or root fungal disease pressure. Chloride sources (potassium chloride, magnesium chloride, ammonium chloride) are of equal value, so which source to use depends on factors such as availability, price, and convenience.

January 1, 2014 – Recognize wheat growth stages
Proper identification of wheat growth stages is fundamental to good management. Growth stage can be important when making N fertilizer management decisions. By the time plants begin to joint (stem elongation) the heads per acre and kernels per head have been determined. Low tiller counts at Zadok's growth stage 25 (before Feeke's stage 3) may call for additional N. Timely N application increases profit potential and minimizes disease susceptibility.

December 20, 2013 – Technology Updates Can Improve Efficiency and Profits
Technology is moving fast these days. Be on the lookout for new innovations that can help cope with the rapidly changing times. Is it time to consider some form of variable rate planting or fertilizer technology, and if so how is it best implemented? There is also a constant development of new apps that can help streamline various decision-making processes. It is sometimes difficult to stay abreast of the continual onslaught of new technology, but it provides seemingly unceasing opportunities to improve farm efficiency.

December 10, 2013 – Watch Trends in Soil Test Levels
Soil testing is important in determining fertilizer needs for the upcoming crop. Regular soil testing is also important in evaluating the larger picture. When a field is tested on a periodic basis trends in P and K fertility levels can be evaluated. Observing trends can help avoid excessive draw-down of soil P and K and other soil related problems that might develop over time.

December 1, 2013 – Wheat Growth Stages
Recognize wheat growth stages. Proper identification of wheat growth stages aids timely applications of nitrogen (N). By the time plants begin to joint (stem elongation) the heads per acre and kernels per head have been determined. Low tiller counts at Zadok's growth stage 25 (before Feeke's stage 3) may call for additional N. Apply N at the proper rate and time to increase profit potential and to minimize disease susceptibility.

November 20, 2013 – Phosphorus Hastens Crop Maturity
Did your corn mature on time this year? Delayed maturity is one sign of P deficiency. Starters containing P can help hasten crop maturity. In fact, where soils test low, fertilizing with P can bring down harvest moisture by 4 to 5 percentage points, thus resulting in more profit due to lower drying costs.

November 10, 2013 – Is Compaction a Problem in Your Fields?
Fall is a good time to check fields for soil compaction. Immediately after fall harvest growers should examine plant roots to determine if soil compaction has limited growth. Look for any abrupt turning of the main root axis that may have been caused by a compacted soil layer. Probing with a pointed steel rod or a hollow soil probe can also help determine the depth and thickness of the compacted layer. If compaction is detected, fall chisel plowing or shallow sub-soiling may remedy the problem. The soil must be dry enough for the tillage to disrupt or shatter the compacted layer. Where appropriate, this practice can improve the rooting environment and thereby increase plant growth and enhance nutrient and moisture uptake.

November 1, 2013 – Fall Application of Fertilizer and Lime
Application of P, K, and aglime in the fall can save valuable time when next spring rolls around. This practice spreads the farmer and fertilizer dealer workload over more time, reduces the risk of compaction from having to apply in wet conditions in the spring, and gives ag lime more time to react before spring planting.

October 20, 2013 – Consider Soil Sampling and Testing this Fall
As harvest of spring planted crops winds down, it’s a good time to reflect on this years fertility practices and consider what changes may be needed for the coming season. One practice that is important in fertility planning is soil testing. Fall is an excellent time to collect and analyze soil samples to aid in fertility management decisions for next season.

October 10, 2013 – Cool Season Grass Phosphorus Nutrition and Magnesium Uptake
The potential for grass tetany occurrence in cattle grazing cool season pastures can be affected by maintaining good P fertility. Maintaining soil test P (Bray 1 or Mehlich 3) levels above about 30 lb/A (15 parts per million) increases magnesium (Mg) uptake by forages. Higher Mg in the forage decreases the risk of grass tetany occurrence. Improved P and Mg levels in forage can also improve milk production and lead to greater calf gains.

October 1, 2013 – Don’t Neglect Cool Season Forage Grass Fertility
Cool season grasses such as annual ryegrass provide high quality forage for cattle and other livestock well into the spring and early summer. When preparing cool season pastures this fall remember that profit from animal gain and performance is a function of both forage quality and quantity, and that complete and balanced fertility is essential for optimizing both.

September 20, 2013 – Fall phosphorus and potassium for bermudagrass
Warm season hay production can export large quantities of nutrients from fields. Fall application of P and K to warm season perennial forage crops is a fertility management approach that insures that the crop has adequate levels of these nutrients when it breaks dormancy in the spring. Additionally, root reserves can benefit from fall application prior to winter dormancy.

September 10, 2013 – Winter wheat nitrogen requirements
Winter wheat requires about 2.4 lb of available N per bushel of yield goal, assuming a 12.5% protein content. For forage production, about 40 lb of N (assumes 2% N in tissue) is required for each ton of wheat forage produced. Assuming a conversion of about 15 lb of forage to produce 1 lb of beef gain, it takes about 1 lb N to produce 3 lb of animal gain. When determining N application rates for winter wheat for grain, forage, or grain and forage production consider factors such as yield goal(s) and corresponding nutrient requirements, soil nitrate-N level, and cropping history.

September 1, 2013 – Phosphorus fertilizer with wheat seed
Placing P in the seed furrow at wheat planting is a popular and effective placement option. In-furrow P is quickly available to the developing seedling and can promote accelerated early season development that can result in substantial increases in grain and forage yields. Factors that affect maximum safe rates of in-furrow fertilizer include fertilizer source, row spacing, and soil texture. For wheat in 7 inch rows there is no practical limit to the amount of P applied, however N+K₂O should not exceed 25 lb/A and should be reduced in sandy or very dry soils by about half. The use of urea containing fertilizers for in-furrow application should be avoided. For more on in-furrow fertilizer application see the Seed Placed Fertilizer Decision Aid at http://www.ipni.net/toolbox.

August 20, 2013 – Nitrogen in winter wheat production
Nitrogen is often the nutrient with the highest potential for limiting winter wheat yield and profit. Inadequate N early in the season results in reduced winter wheat root mass and depth, slow growth and development, smaller leaf size, and reduced tillering. Deficiencies later in the season result in smaller kernels and heads, fewer kernels per head, and reduced grain protein. Splitting applications of N fertilizer between preplant and spring is often the most cost effective and environmentally sound approach to N management. In grain production systems, N distribution is generally recommended at 1/3 of the total fertilizer N requirement preplant, with 2/3 applied in late winter prior to jointing. If the crop is to be grazed, N management will need to be adjusted to provide adequate preplant N for fall and winter forage growth, with topdress N applied in a sufficient quantity to provide enough N to match realistic yield goals.

August 10, 2013 – Phosphorus in winter wheat production
Phosphorus affects winter wheat growth throughout the season in several ways. It’s important in seedling development. The young plant has limited root surface for P absorption so a high concentration of available P in the root zone aids in early-season development. Enhanced availability of P encourages the early season development of adventitious roots. Winterhardiness is improved with adequate P. Abundant P results in an early proliferation of tillers which increases forage and grain yield potential. Also, wheat with adequate P matures earlier and more uniformly.

August 1, 2013 – Nitrogen and phosphorus- equally important for wheat
Which is more important to wheat yields, P or N? Actually, they are equally important. Too little of either one will substantially reduce wheat forage and grain yields, thereby reducing profit. Bottom line- don’t skimp on needed P fertility as you prepare for wheat planting this fall. Be sure this year that wheat does not suffer from P shortage.

July 20, 2013 – Balanced pasture fertility makes for good weed competition
Good weed control in summer pastures starts with a healthy stand. Whether pastures consist of a single forage species or a mixture, a thick healthy stand helps prevent encroachment and establishment of undesirable weed species. Complete and balanced fertilization improves pasture density and health, and thus is an important factor in weed management.

July 10, 2013 – In-season nitrogen on soybeans
Supplemental late season N fertilizer may significantly improve soybean yields in high yield environments. Research in Kansas has shown that where other factors such as water and P and K fertility are not limiting, a small application of N during the period of peak demand (pod fill, R1 to R6) can significantly increase soybean yield, particularly where yield potential is high.

July 1, 2013 – Watch for nutrient deficiencies
Keep an eye out this summer for crop nutrient deficiencies. Each nutrient exhibits distinctive deficiency symptoms. When symptoms appear deficiencies can often be corrected in-season, although some yields loss will likely already have occurred. Particular areas of a field may be more prone to specific deficiencies than others. Also, where rates may have been reduced we need to be especially watchful for problems. Careful crop scouting this season can help in the development of plans for next season.

June 20, 2013 – Plan winter wheat fertility programs now
Now is the time to start planning your winter wheat fertility program. Take soil samples early, while time allows and before other duties take priority. Fertility management for wheat produced for grain versus forage and grain will differ. Remember, regardless of whether wheat is to be used as a dual crop or for grain only, adequate P nutrition is critical to the production of optimum yields.

June 10, 2013 – Mid season foliar potassium on cotton
If midseason foliar K applications to cotton are planned this season remember that solution pH affects uptake and performance. Research has shown that common foliar K sources perform best when solution pH is buffered to levels between 4 and 6.

June 1, 2013 – Maintain adequate potassium for bermudagrass
Split applications of N are common in hybrid bermudagrass hay production. Growers often apply N after each cutting to optimize productivity and improve N use efficiency. Although not as common, splitting applications of K under some conditions may also be advantageous. Bermudagrass requires and removes large quantities of K so maintaining adequate available K levels throughout the season is important. In sandy soils K is subject to leaching, so multiple applications can provide more consistent season long fertility, especially in high rainfall areas.

May 20, 2013 – Bermudagrass nutrient removal
Hybrid bermudagrass has tremendous yield potential. An important factor in realizing that potential is complete and balanced fertility. When planning bermudagrass fertilization programs this season keep in mind that each ton of bermudagrass hay removes about 46 lb N, 12 lb P₂O₅, and 50 lb K₂O.

May 10, 2013 – Phosphorus and potassium on alfalfa
Alfalfa is a high quality forage crop with high yield potential. Phosphorus and K fertility are important factors affecting alfalfa production. When planning alfalfa fertilization programs this season, keep in mind that each ton of alfalfa hay removes about 15 lb P₂O₅ and 60 lb K₂O.

May 1, 2013 – Potassium in cotton production
Potassium is an extremely important nutrient in cotton production. Bolls are major sinks for K. Thus, the need for K increases dramatically during early boll set. About 70 % of uptake occurs after first bloom, and uptake peaks at about 3 to 4 lb K₂O/A/day. Potassium deficiency may be expressed as a full season deficiency, or it may not appear until late season during the period of greatest demand. When a heavy boll load is set, the demand for K may exceed the ability of the soil and leaves to supply it, resulting in a late season deficiency. Mid-season foliar K fertilization can be effective in correcting late season deficiencies.

April 20, 2013 – Fertigation
If fertigation is an option this season, discuss with your dealer what nutrients and quantities will be applied through the irrigation system. Use a “jar test” well in advance of application to test the compatibility of your water with the nutrients proposed for fertigation. Testing prior to application is especially important if P fertigation is planned. Adjusting rates and sources of nutrients can eliminate problems of compatibility between fertilizer and irrigation water. Simple precautions can prevent clogging and fouling of irrigation systems that results in lost time and profit.

April 10, 2013 – Balanced fertility and N use efficiency
Nitrogen use efficiency is a topic of considerable interest these days. One of the most important things we can do to increase N use efficiency is make sure that complete and balanced fertility is in place. For example, high-yield irrigated corn research in Kansas has shown that balancing N, P, K and S increased apparent N recovery from 33 to 75% compared to the N only application. So, to get the most out of every unit of N make sure the need for other nutrients is addressed.

April 1, 2013 – Balanced fertility and water use efficiency
Water use efficiency is an important factor in crop production, especially in periods of drought or in areas with limited irrigation capacity. A balanced fertility program helps maximize water use efficiency since it enables greater production per inch of available water.