Archive for the ‘irrigation’ Category
Posted by romeethredge on September 17, 2015
Posted by romeethredge on June 19, 2015
Peanuts that are older are pegging and some are producing pods. Here are some Ga 06G’s that I photographed yesterday that are over 70 days old. They need a lot of moisture now. Most of our peanuts are not this far along but they still need some rain or irrigation to keep them growing.
Here are some comments from Dr. Scott Monfort, UGA Peanut Scientist about our current situation,
“We have a large portion of our peanut acres in the 30 to 45 DAY range with soil moisture diminishing quickly due to the heat. Although peanuts do not typically need a lot of moisture in the beginning of the season, they do not need to go through a drought stress.
Under the current weather pattern (Extremely Hot and Scattered showers), growers need to apply at least ½ to ¾ inch of water to maintain moisture in the soil profile and to keep the peanut crop moving forward. We do not need to get behind. Also we encourage all growers to scout their fields and keep ahead of any weed, insect, and/or disease problems that develop. “
Posted by romeethredge on June 19, 2015
We are getting fairly close to the end of the watering of our oldest corn, it has begun denting, but the water use is still pretty high. With the heat and winds, the water use is especially high.
In looking at some soil moisture graphs we can see that the corn is still pulling moisture from the field. A good thing about soil moisture monitoring is that you can see the soil moisture increase as the crop slows down on its water use. I looked at a couple of graphs this week and they show continued use by the crop. You can see soil water replenish with irrigation or rainfall and see how it goes down quickly. In some cases it’s hard to keep up. Sometimes it’s deeper that you see the moisture leaving, in other words the surface may seem wet. It’s good to get a shovel to check moisture deeper as well.
Here they are below. They are from client graphs of Certified Ag Resources and Holder Ag Consulting.
Posted by romeethredge on May 7, 2015
Here you can see where I painted the 6th leaf a while back and now its way down and we have corn now 6 to 7 feet tall in our oldest fields. In this field planted on March 11th we are now in the V11 stage. That’s about right when looking at the Degree day chart as we have accumulated about a thousand hours. See chart below showing the hours accumulated since this was planted , about 300 more than the last 2 years.
The tassel is now about to my chin when I cut into the stalk, see second photo, so we will be tasseling before too long. Corn is growing fast but it still has a long way to go, it has only accumulated about 10% of the total dry matter. It’s critical to keep it wet now with these dry sunny conditions.
Posted by romeethredge on May 7, 2015
Dr. Wes Porter, UGA/AU Extension Irrigation Specialist gives us this irrigation injection information.
Traditionally we typically like to apply fertilizers and chemicals using either ground based (both fertilizers and chemicals) or aerial application methods. However, we often times are under a time and suitable field working day constraint when it comes to applying many products. Farmers also typically put more production inputs into irrigation crop land. It’s known that irrigation has a higher yield potential and helps to protect that yield potential especially in dry years. Thus, we want to do a more thorough job and provide the crops under irrigation with a more robust production plan to ensure we capture the full yield potential. Due to excessive rainfall during the growing season and in some cases excessive plant growth and height, it becomes difficult and sometimes impossible to enter a field to apply the proper chemicals and/or fertilizers. In this case the addition of an injection pump for chemigation and fertigation can be very advantageous. A center pivot can typically walk around the field when the moisture level is much higher than can a ground based sprayer. Thus, one main advantage is the ability to apply nutrients at critical periods of crop demand.
One of the most daunting tasks in using a center pivot for chemigation or fertigation is calculating the injection rate of the fertilizer or chemical. The following process and example can be found at https://extension.tennessee.edu/publications/Documents/W303.pdf along with more information about specifics on Fertigation of Row-crops.
Steps for calculating fertilizer injection rate:
Determine the irrigated area (acres)
Determine the required application rate of product (in gallons per acre)
Determine the amount required
Determine the injection rate
For a practical example:
Let’s assume that you want to apply 30 lbs N/ac of UAN-32 through a 1,500 ft long center pivot at a rate of 0.3 inches in 12 hours (one complete circle).
Irrigated area = = 3.14 * 1,5002= 7,065,000 ft2
Divide ft2 by 43,560 to get acres = 7,065,000 ÷ 43,560 = 162.2 acres
Determine application rate: = 30 lbs N/ac ÷ 3.5 lb N/gal = 8.6 gal/ac
Determine required amount: = 8.6 gal/ac * 162.2 acres = 1390.3 gallons
Injection Rate: = 1390.3 gal ÷ 12 h = 115.9 gal/h
Posted by romeethredge on April 20, 2015
We’ve had a lot of rain in the past 10 days. Down near Lake Seminole and in many other spots have had 9 inches or more. Here in Donalsonville we’ve had about 6 inches.
See the chart here from www.georgiaweather.net that shows we, on average would expect to get about 1.5 inches over this time frame (in red). But last year we got this much, another rainy spring.
Even more rainy in 2014 if you look at the last month of data, it was two times more rain. This year we were able to get a lot done before this last rainy spell.
Posted by romeethredge on April 3, 2015
The lows here in Donalsonville last weekend were right at 40 degrees. Some corn turned very yellow for several days and some turned purplish. Growth of snap beans was slowed as well.
Soil temperatures dropped to almost 60 degrees which is still good for corn emergence but too cool for good peanut emergence, for sure. Peanut planting shouldn’t start until mid to late April when we have 4 inch soil temperatures above 68 for 3 days running and no cold weather in the forecast.
I heard this week that in middle and north Georgia they had frost and some young watermelon and other plants were killed.
We are watering some corn. It seems early, but corn does need a half an inch per week when tiny and it increases to an inch per week when it hits 3 weeks of age and the need keeps increasing. If we ever get behind on irrigation it can be hard to catch up with hot, dry days and big plants pulling lots of moisture from the soil and this can hurt yields.
Posted by romeethredge on January 20, 2015
In 2014 we had above average rainfall. But, looking only at the averages is deceiving. I know of several dryland fields that were not worth harvesting this year due to dry weather and the insect and fertility problems that come with dry weather. Why did we have extremely high expenses for irrigation and sleepless night checking on irrigation systems and maintaining them. How can that happen?
We need to remember that we are never very far from an agricultural drought, especially on sandy soils and when the heat and evapotranspiration rates are high.
Let’s look at rainfall data from Donalsonville, Ga.
First let’s look at 2013! It was a very wet year, no argument about that with 79 inches collected, almost 30 inches above average. In the second chart below we look at the rainfall that occurred during the main crop use time and we see double normal rainfall from May 1 to Sept. 1. We had problems associated with too much moisture that year.
Now we will look at 2014 data. Well, we had more than average rainfall for the year, 68 inches total, when our norm is 54 inches. So why did we have severe drought in our crops and high irrigation expenses?
The second chart below answers that question. We didn’t get the rain when it was needed. We had half the normal rainfall when summer crops needed it from May 1 to Sept 1, even though the year was a surplus rain year.
To view weather and rainfall data like this, go to http://www.georgiaweather.net/.
Posted by romeethredge on January 19, 2015
What about our aquifer that we irrigated so much from this summer? It allowed us to make good yields on land a few feet from where crops were not harvested due to dry weather.
Well, the Floridan aquifer was well recharged going into the summer drought. This chart shows the whole year of 2014 in terms of well water levels. You can see how the level (blue line for 2014) dropped, but not much below average levels(gold triangles). Then our rains starting in early September have recharged the aquifer nicely again.
Today, it’s 23 feet down to water in this Miller county test well, which is about 8 feet better than normal for this time of year.
Posted by romeethredge on August 7, 2014
This first week of August (if the peanuts were planted by May 1), is the peak of the water use curve, requiring about 2 inches per week. The good news is that we’re about to move past the peak water use period and start requiring slightly less water in the oldest fields.
If your peanuts were planted 2-4 weeks later they will move into the highest water use period soon. Please see the figure below for the ranges of peanuts planted from late April (yellow) and peanuts planted in middle May (blue).
Thanks to UGA Scientists, Wes Porter, Gary Hawkins and Calvin Perry for most of this info.