Update on Brazil Soybean planting.

By Eduardo Paim: 

I'm here looking at the weather and wondering when I should send you news of our soy planting. We still do not know if we will have a good grain yield, the rains are undefined and the sun very hot. Many farms are replanting soybeans, it has been planted and due to lack of rain the seeds will die. Soybean planting is not yet 100% complete and this will make the area of ​​second crop corn shrink in Brazil. At this moment I can say that we did not start well! It reminds me of the year 2016/2017, little rainfall and very hot. "It rains in the living room and not in the kitchen"!
I don't see mud on farm roads, just dust. There is little rain here.

Potassium for Crop Production

Originally written for CCA Soy Envoy Blog 

Having spent my time as a CCA Soy Envoy writing about micronutrients, sulfur, nitrogen and phosphorus, it seems appropriate to close out the year focusing on potassium. Of the plant nutrients, potassium is part of the big 3—nitrogen, phosphorous and potassium (NPK). When I run soil tests in my area potassium is the most likely to be low, although some soils I work with can be high and stay high. 

Potassium helps plants withstand drought damage. It is also credited with general plant health and preventing lodging. Potassium helps the plant produce starch and transform sugars. This nutrient is also essential for photosynthesis. Potassium deficiency is characterized by yellowing and then tissue death starting at the edges of leaves in both corn and soybeans. This Iowa State University Bulletin has more information on potassium deficiencies. They go into some explanation of causes of potassium deficiencies other than low soil test.

In past years we have seen some drought-induced deficiencies in fields. Fields with good potassium levels to begin with seem to resist that deficiency better. We also thought we saw some compaction-induced deficiencies because of working and planting in wet soil conditions this spring. Several years ago, University of Illinois (UIUC) researchers hypothesized that we do not need potassium fertilizer. Research from other credible sources including the International Plant Nutrition Institute has called the researchers’ premise into question and disproved some of their findings. Emerson Nafziger, Ph.D., also argues for potassium fertilizer in this article.

Potassium is common in our Illinois soils because it is present in the crystal lattice of a prevalent clay mineral, illite. The nutrient seems to move in and out of the lattice depending on moisture. This makes potassium soil testing imperfect, but it is all we have to establish a scientific basis for determining fertility needs.

One reason that we test soils more often than the university recommendation is that it helps us keep better track of potassium. It has been my experience that crops do respond to potassium when soil test levels are below 230 pounds per acres. Ideal levels are considered to be 300 to 400 pounds per acre in Illinois. Potassium is critical to help weather a drought. Levels need to be high because availability goes down when soil is dry.

We do have clients with soils that have not needed potassium fertilizer in twenty years or more. These growers haven’t had any apparent yield loss and the test levels remain high. We also have clients who have low potassium test levels who have benefited from potassium fertilizer. 

One of my clients raised 80 bu/A wheat a few years ago after increasing his potassium fertilizer on that field. We do find that potassium levels sometimes remain low for several years as we attempt to build the nutrient up. We will then have a sudden and unexpected rise in soil test potassium. I will sometimes suggest 100 pounds per acre of potassium fertilizer to prevent wild swings in soil test levels even though soil tests would seem to indicate we can skip a year.   

Iowa State University has endorsed a moist soil test where they do not let the soil dry down. I have no problem with using the moist test, but we continue to use the Mehlich 3 extraction. I am not ready to give up on potassium testing even knowing the limitations of the test. We are going to continue to test frequently and recommend potassium fertilizer on soils that have low soil test levels, making adjustments as needed.

Brazilian Soybean Planting,

November 4, 2019

By Eduardo Paim

Here in Mato Grosso we have many farms with little rainfall. We are looking at the farms being very careful with the soy planting and the moisture that is in the ground. We are already seeing some farms that believed that the rains would come and planted the soybean seeds and lost part of what was planted! I see farms that germination is not good, some seeds are born and some die. Too much rain in southern Brazil, this can hurt the grain crop there too. Now we are looking at how much second crop corn we can plant, considering that soy planting has been delayed due to lack of rainfall! I am also realizing that we are getting about 15 days without rain and very sunny and intense heat. If I'm not mistaken in the 2015/2016 crop it was like that, it was raining a lot and the water didn't enter the ground to retain moisture, soon after there was an interval of 15 or 20 days without rain and very hot heat and there was a big reduction in production. of grain from Brazil.