Archive for the ‘Fertilization’ Category
Posted by romeethredge on November 15, 2013
Preplant Nitrogen fertilizer will depend mostly on what was just harvested from the field this season. UGA Extension Grain Agronomist, Dr. Dewey Lee, says the amount of N we need depends on previous crop. Below are recommended N amounts:
Cotton – 35 to 40 lbs/ac
Corn or Fallow – 30 to 35 lbs/ac
Soybeans – 15 to 20 lbs/ac
Peanuts – 0 to 15 lbs/ac
Tillers produced in the fall generally produce the most grain per unit area. It is important not to over-fertilize with N in the fall as it may cause excessive growth and result in winter injury.
Total N will be between 100 and 130 lbs per acre. We need most of it in late January and February as one or two sidedressings – depending on tillering.
Timing of N fertilization should be based on the pattern of uptake by the crop. Demand for N is relatively low in the fall but increases rapidly in the spring just prior to stem elongation. Therefore, make the fall applications of nitrogen at planting, and the remaining N prior to stem elongation. Use the lower rate of fall applied nitrogen at planting on heavier-textured soils and the higher rate on sandy soils.
Other nutrients should be applied according to a soil test preplant.
Since 65% of the total P uptake and 90% of the total K uptake occurs before the boot stage, these nutrients should be applied according to soil test before planting and thoroughly incorporated into the rooting zone.
Posted in Fertilization, Wheat | Tagged: fertilization, wheat | Leave a Comment »
Posted by romeethredge on October 11, 2013
Bermudagrass Stem Maggot is a new pest that has only been in the US for a few years. This is the first time I’ve been sure that I’ve seen it in deep southwest Georgia. This Alicia Bermuda pasture has stem maggot damage as well as Leaf Rust due to the leaching and use of potassium causing a deficiency that goes along with the leaf rust. The Stem borer feeds into the stem and usually kills the top 2 or 3 leaves on the plant. There’s not a lot you can do about it but go ahead and make a cutting. there is ongoing research on insecticide sprays. You can go to a factsheet and a video by Dr. Dennis Hancock, UGA Forages Scientist, concerning this problem by going to our UGA Forages site. http://www.georgiaforages.com/
Posted in Entomology, Fertilization, Forages | Tagged: entomology, forages | Leave a Comment »
Posted by romeethredge on August 8, 2013
A big fertility issue with peanuts this year that was caused by the unusually wet weather is delayed gypsum/(landplaster) applications.
Dr. Glen Harris, UGA Extension Soil Scientist, gives us the latest info concerning this.
The recommended time to apply gypsum is early bloom, which normally occurs around 45 days after planting (or maybe as early as 30 days after planting). Many peanut fields were simply too wet to apply gypsum at this time. How late is too late to apply gypsum ? Again, since the “peak pod fill” period is 60 to 90 days after planting, and this is time when developing are “sucking in” calcium dissolved in the soil solution directly through the hull, once you get to 100 days after planting, it is definitely too late to apply gypsum. What about 60 days after planting ? Well, 60 days after planting is better than 70 days after planting… which is better than 80 days after planting (you get the idea).
Two other things to keep in mind if you are considering a late (60-90 days after planting) gypsum application though are 1) will you do more damage running over lapped vines than you gain by adding calcium?, and 2) Did you really need a gypsum application in the first place? Remember that if you had at least 500 lb/a of soil test calcium in the pegging zone (top 3 to 4 inches of soil) AND a calcium to potassium ratio in this soil sample of at least 3:1 or better, AND you are not producing peanuts for seed….than you technically did not need a gypsum application at all. I hear about many soil samples being in the 700, 800, 900 even 1000 lbs of Ca/a and with all the rainfall we have had there should be plenty of soil water in the pore space to dissolve the soil calcium and get it into the nuts.
Posted in Fertilization, Peanuts | Tagged: fertility, peanuts | 2 Comments »
Posted by romeethredge on August 8, 2013
The answer to last week’s question is Magnesium deficiency. Muscadine grapes don’t need a tremendous amount of this nutrient but they do need some every year and so I recommend some Epsom salts, Magnesium sulfate, around every plant every year. Keeping your plants limed with dolomitic limestone helps as well.
Here’s the question of the week. What types of birds are these that I photographed here in Seminole County a couple of weeks ago at the edge of a pasture?
Posted in Fertilization, Wildlife | Tagged: Wildlife | 2 Comments »
Posted by romeethredge on June 12, 2013
Our oldest cotton is squaring now so it is time to start thinking about sidedressing fertilizer. Here’s some that was being sidedressed today.
The following is taken from Dr. Glen Harris, UGA Extension scientist’s, writings in the 2013 UGA Cotton Handbook. The total Nitrogen rate should always be applied in split applications. Apply 1/4 to 1/3 of the recommended N at planting and the remainder at sidedress. The preplant or at planting N application is critical for getting the crop off to a good start and ensuring adequate N nutrition prior to side-dressing.
Sidedress N between first square and first bloom depending on growth and color (toward first square if slow growing and pale green, toward first bloom if rapid growth and dark green). A portion of the sidedress N can also be applied as foliar treatments or through irrigation systems. No N should be soil-applied (either top dressed or through the pivot) after the 3rd week of bloom. Studies have shown that uptake of soil-applied N from by cotton roots is basically ineffective after this critical point.
Posted in Cotton, Fertilization | Tagged: cotton, fertilization | Leave a Comment »
Posted by romeethredge on May 10, 2013
We have seen more corn nutrient problems than usual. There’s been Phosphorus deficiency, especially where pop up fertilizer wasn’t used. It is harder for the plants to take up in cool conditions. Also there’s been some Magnesium deficiency, with striped leaves and it’s sometimes a temporary striping condition when we get fast growth. Magnesium is more available to plants at higher pH’s. A plant tissue analysis is often needed to figure out these problems.
Then corn also needs Zinc, and we’ve seen a little Zinc deficiency in some fields. We don’t need much Zinc due to the fact that the plant doesn’t need much and because we may grow peanuts in the same field next year and they are sensitive to too much Zinc. Often growers can use a micronutrient pack in preplant fertilizer to suppply enough of the micronutrients. Zinc is more available to plants at lower pH levels. So overliming may actually cause Zn problems in corn. I saw a case this week where they have new ground where they burned old trees and brush and they limed the field well and where these burn piles were, the Zinc deficiency problem is worse. We often get higher pH’s in ashy burn pile areas. A foliar spray or 2 of Zinc will often rectify the problem.
Posted in Agriculture, Corn, Fertilization | Tagged: corn, fertility | Leave a Comment »
Posted by romeethredge on April 27, 2013
Last week I had a photo of purple corn beside some normal looking corn. In this field the grower did not use pop up fertilizer ( fertilizer put close to the young plants that usually contains Phosphorus). He did use a good dose of preplant Phosphorus. At this spot in the field he changed corn hybrids and that is what we see here. One row is one variety and the other one is another variety. We ran a tissue analysis and a soil test here and the nutrients in the soil, including P were at sufficient levels. However the plant tissue was deficient in Phosphorus. We know that cool temperatures like we were having makes it difficult for plants to take up phosphorus. We also know that different corn hybrids sometimes respond differently to low nutrients in the tissue.
Another kink here is that the seed company says that the corn hybrid here that is purple sometimes has a buildup of anthocyanins, causing changes in plant color, with warm weather followed by cold rain and weather. Since the tissue came back low we can say here the color was likely caused by low P due to cool conditions and the hybrid response to it.
Here’s a photo with the purple corn in the foreground and the green corn in the background.
Posted in Corn, Fertilization, vegetables | Tagged: corn, fertility, vegetables | 1 Comment »
Posted by romeethredge on April 18, 2013
Corn is finally straightening out. We’ve had some good weather right here recently. Some corn we checked today is in the V5 stage and is getting tall. Weeds are growing well too and palmer amaranth is emerging. Lots of corn sidedressing is going on and some fields that haven’t had it are looking somewhat deficient. Weed controls are going out as well when the wind permits.
Posted in Corn, Fertilization | Tagged: corn, fertilization | Leave a Comment »
Posted by romeethredge on March 4, 2013
Wheat is really moving along.
I looked at many fields today and all are jointing and many have some flag leaves out. I even saw a couple of heads trying to show themselves. I didn’t find any Stripe Rust, thankfully. There is still plenty of powdery mildew out there, and if it climbs to within a couple of leaves of the flag leaf, we may have to spray an early fungicide. We usually like to delay fungicide applications until the heads are out to get disease control on them as well as the flag leaf.
I’m not too worried about recent leaching rains on the fertilizer except for on deep sandy soils where some may need some additional fertilizer if it was done right before the rains, but each situation needs to be carefully considered and some tissue testing may need to be done. Fertility looks good in fields I was in today to the point where there was some slight lodging where the fertilizer truck turned around near the edges. These were not sandy fields.
Slight lodging(falling) where fertilizer truck turned around and put a little extra.
Posted in Fertilization, Plant Pathology, Wheat | Tagged: fertilization, Plant pathology, wheat | Leave a Comment »
Posted by romeethredge on December 21, 2012
We’ve had some discussions lately about liming and liming materials. Sometimes Hi Cal (Calcitic ) Lime has been used at times as a calcium source for peanuts before planting and it works pretty well and it also raises pH. We don’t want pH too high however, we start getting over 6.7 and we begin seeing some induced problems with things like Manganese (Mn) deficiency.
Dr. Glen Harris, UGA Extension Soil Fertility Scientist, has the following to say about liming and changing soil pH.
Dolomitic lime (that has 6 % or more Mg) is still the most common liming material used in
Georgia and provides magnesium (Mg) as well as calcium (Ca) and a pH adjustment.
Calcitic lime (less than 6% Mg) is becoming more popular and may be used in cases where high
soil Mg levels occur, it has been used as a calcium source in peanuts preplant.
If calcitic Lime is used for consecutive years, soil test Mg levels should be tracked closely with soil testing.
As soon as soil test Mg levels start to drop out of the high range into the medium range, the use of dolomitic lime should be resumed. The reason for this is that dolomitic lime is the most economical source of Mg fertilizer.
Posted in Agriculture, Crops, Fertilization | Tagged: fertilization | Leave a Comment »