Tuesday, July 19, 2016

Parker's Report: Week 10

Week 10: Trimming and Tractors
July 11-15, 2016


                  Monday dawned bright, hot, and humid. I arrived at the barn and was greeted by happy nickers from the horses. After putting oats and a hoof supplement in each stall I let the eager horses in the barn to eat. I took Summer and Bonnet and trimmed their hooves once they were done eating. I decided to trim two or three horses every morning over the course of the week. When I was done I let all the horses out and swept out the barn as usual. Then I went and got on my 4555 and took it to the North Alfalfa pasture. The Dallisgrass had gotten thick and a group of cows were about to be put in it. I made four laps around the circumference of the front section before cutting along the fence line in nice straight lines across it. To me the straight lines look really pretty. On Tuesday it was Willie, Ms. Kitty, and Ginger’s turn to have their hooves trimmed. When I has done with them I headed back to the North Alfalfa to finish. This pasture is rather odd to bush hog because there are three sections to it. Each one is divided by a long, deep ditch/ creek surrounded by trees. The cows easily pass from section to section but there is no place to cross in the tractor. Instead I had to go into the next pasture and circle around to the gate leading into the next section. While I was in the middle segment and cresting the hill, movement from beyond the fence caught my eye. I looked over and a large whitetail buck gracefully soared across the open pasture. He had at least eight thick, velvety points on his antlers and was beautifully broad and muscled. I was in such surprise and awe that I didn’t think to pull out my phone and snap a picture until after he had disappeared into the woods. The sight of such a majestic creature made my day. That afternoon as I was in the back of the pasture a storm blew in. I love watching them build at least once every week. The sky is blue with white clouds everywhere most of the day. Around 2 or so they’ll start creating massive towers with many different nooks and crannies way in the west. As they approach the clouds turn from white to dark gray. The temperature drops to a pleasant cool. Eventually a solid deep blueish, purpleish gray overshadows the land. Refreshing rain begins to fall. That Tuesday a light sprinkle was all I received in the pasture that I was in. I was close to finishing so I opted to push through it. However, I kept a close eye on the sky because it was darker than normal and I could see lightning around me in the distance. I completed bush hogging the North Alfalfa without incident and called it a day. On Wednesday, SisterBear, Bubbles, and Mona all had their turn to have their hooves trimmed. Sister made it very clear that she did not appreciate being left in her stall longer than normal as there were several piles of fresh manure waiting for me when I finished. When I finished cleaning the stalls and sweeping, I moved my bush hog across the farm to the back of the lane. I cut the front portion next to the road before moving around behind the creek to the back part. To my surprise it had already been clipped. I checked the next pasture over (the Mary Alice) as it was next on the list. It had been bush hogged as well so I moved to the back of the lane. It was already late in the day but I had just enough time to make my four rounds around the perimeter. That set me up perfectly for the next day. Once I trimmed Wes, Buddy, and Dixie I was able to cut in straight lines parallel to the long fence side. This pasture was a challenge because in some places the grass was so short I couldn’t see where I had already passed over. There were several instances where I thought I was cutting along the right line and would suddenly realize that I was passing over a place I had already been. Despite the challenge, the pasture was completed and looked nice according to my specifications. It reminded me of a freshly vacuumed carpet. Friday was full of lots of odd jobs. I finished trimming my last three horses: Wanda, Sam, and Trudy. (Trudy is doing excellent by the way. You can’t even tell she had an abscess unless you know where to look.) I mucked stalls and took special care in sweeping since it was the weekend. I then bush hogged the old Brahman bull pasture and the cow trap next to the North Alfalfa pasture. When those were finished I took my bush hog and tractor back to the shop and cleaned them off. Mr. Mike gave me a life back to my truck and we talked about irrigation. He showed me the reports that the soil moisture sensors were sending to his phone. He also informed me about several of the projects going on on the farm concerning new technology and how to best utilize the water that they have to produce the most crops that they can. Crops require different amounts of water at different times in their life cycle. Corn’s water requirements are pretty well known. However, soybean’s are not known as well. I ended the day by washing off Seth’s truck and cleaning out all the mud from the inside. Some visitors were in town and while touring the farm got caught in a heavy rain the night before. Needless to say, things were very muddy. It was worth it though as the farm received between 2 and 3 inches of rain.

Pictures Below






The Importance of Accounting for Precipitation When Using Soil Moisture Probe Based Irrigation Scheduling In the Sub-Tropical Climate of the Southeastern United States by Parker Grace Adams

The Importance of Accounting for Precipitation When Using Soil Moisture Probe Based

Irrigation Scheduling In the Sub-Tropical Climate of the Southeastern United States

Parker Grace Adams



Abstract

This paper discusses the importance of irrigation scheduling and the various methods

available to determine when irrigation should occur. Irrigation scheduling is an extremely

beneficial technology introduced to the agricultural industry in the past several decades that has

allowed the cultivation of land not in close proximity to water as well as improved the crop

yields of that cultivated land. But unrestricted irrigation can lead to a soil excessively saturated

with water, ultimately reducing crop yields. Therefore, in the interest of producing maximum

crop yields as well as reducing the money, water, and energy inputs used in irrigation, it is

prudent to schedule irrigation times to receive maximum benefits. Soil moisture probes are often

used to determine how much water to apply based on the amount of moisture available in the

ground. When that moisture reading is lower than a specified point irrigation systems can be

turned on. In arid and semi-arid climate regions were rainfall is scarce a schedule of irrigation

can be created from soil moisture probes. However, in the sub-tropical climate of the

Southeastern United States putting together an irrigation schedule based solely on soil moisture

probes is a bit more complicated due to the noteworthy amount of rainfall received during the

growing season. This rainfall must be taken into account when irrigating so as not to over-water

the crops. A simple check-and- balance system can be used to determine the proper amount of

water application and derive an irrigation schedule. In this paper, the importance of using both

weather data and soil moisture probe data to derive an irrigation schedule for crops grown in the

sub-tropical climate of the Southeastern United States will be explored and expounded upon in

addition to the other factors which contribute to efficient irrigation scheduling.


Keywords: irrigation scheduling, soil moisture probes, rainfall, weather data, balancing method,

sub-tropical climate


Introduction

Irrigation has been an invaluable resource to farmers for many ages. Irrigation practices

have continually been improved upon enhancing benefits as well. Crop yields have increased

under the practice of irrigation and have done so further under precisely scheduled irrigation

events. Related factors of production such as input costs of water and energy use are reduced.

Nutrient, fertilizer, and pesticide losses are lowered as well. While irrigation and irrigation

scheduling have many benefits, there are a few concerns that must be taken into account.

Irrigation occurs in conjunction with precipitation and as such over-watering can easily transpire.

Over-watering results in decreased crop yields and increased input costs. Using soil-moisture

probes, irrigation can be precisely scheduled to avoid over- or under-watering crops. However, in

the subtropical climate of the southeastern United States, annual rainfall is high and soil moisture

probes cannot detect or predict coming storms. Therefore, it is important to weather data with a

soil moisture probe based irrigation scheduling system in the Southeast.


Irrigation

Water is arguably the most important and greatest limiting factor in plant growth and

crop yield. Without water the plant will not grow. Plants receive their needed supply of water

through precipitation events like rainfall or other natural sources such as ground water. In

production settings, irrigation is used to supplement precipitation. Sometimes this is because

precipitation events alone do not provide the plant with its needed amount of water. In most

cases irrigation supplements rainfall because it increases crop yields (Knappenberger 5).

Increased crop yield can result in an increase in profit or a decrease in inputs such as the amount

of land required to produce the same amount of crop. Therefore, irrigation is considered a

beneficial and often necessary farming practice.


Hazards of Over-Watering

Irrigation can easily result in an overwatering of crops. Overwatered crops have a lower

crop yield. This occurs due to the over-saturated moisture content of the soil. An over water-

saturated soil often leads to “plant disease, nutrient leaching, and reduced pesticide

effectiveness” (Evans 1996).

Furthermore, over-irrigating crops leads to other unfavorable effects. Over-irrigation

wastes water, a declining, valuable resource (Evans 1996). Water for irrigation is pulled from

ground water reserves. This can be a water body such as a lake, a reservoir, or an aquifer

(Kebede 2918). Many producers in the delta region of Mississippi use the Mississippi River

Alluvial Aquifer to irrigate their crops, but the Aquifer is not being replenished to meet the

demands of producers (Kebede 2918). With proper techniques, water can be applied in an

efficient method. One of the most important methods of efficient irrigation is the timing of water

(Evans 1996). The timing of water application to crops has been shown to not only increase crop

yields but decrease the water required as well (Harrison 2005). Prudent scheduling of irrigation

times can also minimize wasted water in the form of runoff and percolation losses (Evans 1996).

Minimizing these losses assists in sustaining irrigation water reserves. Scheduling irrigation

leads to an efficient use of water as a resource.

Another negative effect of over-irrigation is wasted energy use. Energy use is related to

irrigation and can be translated into a dollar amount. Irrigation systems require energy in the

form of electricity to run including pumping water from a reserve to the field. If over-irrigation

occurs, not only is water being wasted which decreases crop yields, but energy is being wasted in

running the system that is over-irrigating the crops. It is a double loss.

Energy can be saved by “no longer pumping water that is [being] wasted” (Evans 1996).

Mentioned previously, the amount of water needed can be reduced by applying it at opportune

times. By not using as much water, irrigation systems are not running as long and therefore, the

energy required to run the system is reduced. Decreasing both the energy and water required for

irrigation decreases input costs. Decreased input costs translate into an increase in profit (Evans

1996). That increase in profit is further maximized by the increase in crop yield stemming from

the efficient irrigation practices.


Using Soil Moisture Probes to Schedule Irrigation

The purpose of irrigation scheduling is to “determine the timing and the amount of water

to be applied based upon the crop’s water needs, soil water storage capacity, and climate

conditions” (Kebede 2922). Soil moisture probes are often used to schedule irrigation (Kebede

2923). They are based upon the moisture content in the soil. Plants experience stress when water

levels in the soil dip below a certain amount (Martin 2009). A stress level threshold is often set

for crops at a matric potential of 50kPa, below which “plants are considered to be under stress”

and which is why “[it] is considered as an irrigation trigger” (Knappenberger 5). Soil moisture

probes can be used to detect the matric potential of the soil in effect measuring the moisture

available in the soil to the plants. This information can be used to determine when to begin

irrigation and how much water to apply (Kebede 2922).

Soil water storage capacity plays a role in scheduling irrigation due to the differences in

the ability of different soils to hold water (Harrison 2005). For example, sandy soils hold less

water than clay soils. Therefore a crop grown in a sandy soil will need to be irrigated more

frequently than a crop grown in a clay soil (Harrison 2005). This volume ultimately dictates

irrigation, as it determines how much water can be made available to crops as stored in the soil

(Evans 1996). Once the soil water storage capacity is reached, excess water becomes runoff and

percolation (Evans 1996). Again, this harkens back to wasted energy and water that translates

into increased input costs. Furthermore, runoff and percolation reduce pesticide effectiveness and

are a cause of nutrient leaching (Harrison 2005). The water storage capacity of a soil plays a part

in overwatering as well. Excess soil moisture results in plant disease and decreased crop yields as

stated previously (Harrison 2005).

Associated to the amount of water available in the soil, moisture probes account for the

amount of water used by the plant (Kebede 2922). This crop water use is defined as “the amount

of water given up to the atmosphere by transpiration through plant leaves and evaporation from

the soil and plant surfaces” (Kebede2922). These two processes, evaporation and transpiration,

are combined in the term evapotranspiration (Kebede2922). Daily crop water use changes

throughout the growing season depending on different factors such as the life stage of the crop,

temperature, and wind-speed (Kebede 2922).

In arid and semi-arid regions such as the western United States, soil moisture probes

work very well in conjunction with irrigation systems. Once the probes detect that the soil

moisture is below a set threshold amount they trigger the irrigation system to begin irrigating

(Martin 2009). The threshold value is usually set above the stress-inducing matric potential value

so as to “insure that water stress will not be so severe as to cause any appreciable yield losses”

(Martin 2009). Thus, the whole system can be automated. This is in part due to the minimal

amount of annual rainfall that occurs in arid/ semi-arid regions and the even smaller amount

which occurs during the growing season (NCSU 2012). Because the annual rainfall is minimal,

overwatering is not a concern. In effect, with precipitation not a concern irrigation scheduling

operates in a controlled environment where efficiency is increased.

A soil moisture probe based irrigation system can work in sub-tropical areas such as the

southeastern United States. Jason Krudtz, a Mississippi State University irrigation specialist at

the Delta Research and Extension Center in Stoneville, Mississippi, is a huge proponent of soil

moisture sensors. In an article on the use of the sensors in Mississippi Krudtz explained their

efficiency. “‘It sounds absurd to say that you can apply half the water you normally apply and we

can maintain or improve your yield almost guaranteed and improve your profitability by cutting

way down on your water cost,’” Krutz said at the 2013 MSU Row Crops Short Course (Coblentz

2013).


Accounting for Precipitation

The main downfall of using soil moisture probes to schedule irrigation is they cannot

detect coming precipitation events. Annual rainfall must be considered when scheduling

irrigation. The southeast — including Alabama, Arkansas, Georgia, Louisiana, Mississippi,

North Carolina, South Carolina, and Tennessee — receives an annual rainfall amount of between

40 and 70 inches (NCSU 2012). While annual rainfall is high only 30% occurs during growing

season (Kebede 2918). Therefore, irrigation is used to supplement precipitation and maximize

crop yield. If irrigation were to occur without consideration for precipitation overwatering would

transpire leading to reduced crop yield and decreased efficiency. Therefore, combining a

moisture probe based system with a weather based system is wise.


Combining Scheduling Methods

In its simplest form, irrigation scheduling occurs in what is commonly referred to as the

checkbook method. The checkbook method is a simple accounting approach that seeks to

balance the crops’ water needs with incoming water sources based on water levels in the root

zone (Evans 1996). Water inputs such as irrigation and precipitation are compared against water

outputs such as crop water use, evapotranspiration, and percolation losses (Harrison 2005).

Building upon the checkbook method, other factors may be included. Annual rainfall that

occurs during the growing season in the southeast should be taken into account. The timing of

rainfall is most important as it has a major impact on irrigation decisions (Evans 1996). Irrigation

can be automatically scheduled to occur at certain times, however, these times do not account for

precipitation occurrences. Chances are that irrigation and precipitation will overlap causing over-

watering to occur reducing overall efficiency and crop yield (Evans 1996). In some instances, it

might be more wise to postpone irrigation in anticipation of a precipitation event than irrigate.

Final judgement is left to the producer.

More complex methods and models include factors such as wind speed, temperature,

solar radiation, past weather data, evaporation estimates, crop water use and more (Kebede

2924). One such model is the Mississippi Irrigation Scheduling Tool or MIST (Kebede 2924).

Many more programs exist, most are programmable and calibrated to local areas.


Conclusion

Irrigation scheduling requires knowledge of soil types, soil moisture capacity, crops, crop

stress, the potential yield of a crop if it remains stressed, and system operation. Scheduling is

often used by producers to maximize their crop yields while simultaneously reducing their input

costs. Other benefits occur such as minimized runoff that prevents nutrient, fertilizer, and

pesticide losses. Irrigation scheduling often utilizes soil moisture probes to determine when

irrigation should occur based on the amount of moisture in the soil. In the sub-tropical region of

the southeastern United States weather events play a role in scheduling irrigation. Annual rainfall

is high enough in the growing season to risk over-watering when irrigation also takes place.

Therefore, it is wise and advantageous to use soil moisture probe based irrigation and weather

data when scheduling irrigation events.



References

Coblentz, Bonnie, 2013 “Moisture sensors are key part of efficient irrigation” Mississippi State

University Extension, Mississippi Agricultural News, Accessible at: http://msucares.com/

news/print/agnews/an13/20131217_irrigation.html, Accessed March 25, 2016

Evans, Robert; Sneed, R.E.; Cassel, D.K.; 1996, “Irrigation Scheduling to Improve Water and

Energy Use Efficiency”, North Carolina Coorperative Extension Service, AG 452-4,

Accessible at: https://www.bae.ncsu.edu/programs/extension/evans/ag452-4.html,

Accessed March 25, 2016

Harrison, Kerry, 2005, “Irrigation Scheduling Methods”, University of Georgia Extension, B

974, Accessible at: http://extension.uga.edu/publications/detail.cfm?number=B974,

Accessed March 25, 2016

Kebede, H., Fisher, D.K., Sui, R. and Reddy, K.N. (2014) “Irrigation Scheduling in the Delta

Region of Mississippi: Current Status and Strategies to Improve Irrigation Efficiency”,

American Journal of Plant Sciences, Vol.05 No20(2014), Article ID: 50005, pages 2917

-2928, Accessible at: http://file.scirp.org/Html/2-2601651_50005.htm, Accessed March

25, 2016

Knappenberger, Thorsten; Ortiz, Brenda; Delaney, Dennis; 2015 “Improvement of Irrigation

Management on Alabama Black Belt Soils”, Auburn University, pages 1-6

Martin, Edward C., 2009, “Methods of Measuring for Irrigation Scheduling—When”, The

University of Arizona, Arizona Cooperative Extension Arizona Water Series No.3, pages

1-7, Accessible at: http://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1

220.pdf, Accessed March 26, 2016

North Carolina State University, 2012, “Southeast Precipitation”, Climate Education for K-12,

Accessible at: https://climate.ncsu.edu/edu/k12/.SEPrecip, Accessed March 28 2016

Parker's Report: Week 8

Week 8: Publicity and Pigweed
June 27-31, 2016

                  I stepped out of my truck Monday morning and sweat started pouring from my brow. It was going to be a long, hot, humid day and I hadn’t even done anything yet. I began my morning routine feeding the horses and cleaning the barn. Seth and Mr. Mike then situated me on the small sprayer attached to the back a tractor. They showed me how to run it and which chemicals in which proportions to mix. I was on a mission to kill pigweed. Technically the plants I was after were spiny amaranth (Amaranthus spinosus) but are in the same family as what people commonly call pigweed. The spiny amaranth had grown up around the feeding troughs and spots where hay had been fed over the winter. It is ugly as a weed in general but more importantly causes ring worm in cattle. Therefore, it needed to be eradicated. The chemicals I used where a combination of RoundUp, surfactant, and a nitrogen based compound. The nitrogen essentially tricked the plant into thinking that the RoundUp was good for it so it would absorb it more quickly. I had fun driving through all the pastures spraying the pigweed. It took me a while to get the hang of spraying. Unlike bush hogging there wasn’t a clear indication of where I had driven let alone where the spray had fallen. Most of the time I could see my tire tracks but sometimes I couldn’t. From there I had to judge to the best of my ability how far out the spray had fallen and how close I needed to drive so that everything was covered. I kept having to remind myself to trust my tractor and the sprayer to cover everything. Towards the end of the day a storm blew in. I had watched it build all afternoon. The wind whipped around and it sprinkled a few large drops. Lightning struck in the next pasture over. However, it passed me by so I continued spraying until the end of the day. The skies were a dark and ominous gray on Tuesday. I saddled up SisterBear and Ginger and Mrs. Dee and I moved the Quad cattle from one pasture to another. After cleaning the barn I brought in the big 4555 tractor to the shop to have a new muffler put on. Then I mowed the yard before the rain finally began to fall. While I was out mowing the board of directors from Alabama Ag Credit came by for a visit. They were celebrating 100 years of business. The main reason for their visit was to tour the farm. They helped with the finances for building the big 120-acre reservoir on the farm that collects water during the winter and supplies it to the irrigation systems during the growing season. While Alabama receives close to 60 inches of precipitation a year, most of it occurs during the non-growing season. The reservoir collects this water and saves it for later. This way the irrigation system can not only provide water during drought but allows it to provide water in the correct amount and at the most opportune time. Water in the right amount and at the right time is vital to crop production. It is a big factor in increasing overall crop yield. On Wednesday a group from the United Soybean Board came to film. I saddled two horses for Mrs. Dee and I to move a group of bulls as part of the footage. Mr. Matt was there dusting crops in his plane and showed off for the camera. While the filming continued I returned to spraying down pigweed. Even though it had only been two days, the pigweed I had already sprayed had turned a sickly shade of yellow and begun wilting. I felt a keen sense of pride knowing that I had done a good job. Part of the reason I enjoyed spraying so much was because I got to watch the cattle. I always assume cattle don’t have personalities, at least not as apparent as say horses or dogs. However, the more I work with them the more I see their quirks. Late in the afternoon as I was spraying my last two pastures I heard a loud pop. I thought it was just a normal sound from bumping around but as I turned around to check my spray pattern I realized there wasn’t one. I stopped to see what the problem was and quickly discovered that what I called “the pressurizer” had fallen off. I thought I knew how to fix it but was afraid that I might be wrong and end up causing a bigger problem. Just to be on the safe side I made my way back to the shop and put the tractor up for the night since everyone had already gone home for the day. If Monday was like a sauna then Thursday was perfect. It was warm but with a cool breeze blowing. When I would drive past a hay trap it smelled and felt like a flawless fall day. Mr. Mike helped me fix the pump that had fallen off after I had taken care of the horses. All set to go, I finished the last two pastures in no time at all. That afternoon I put a bale of hay out for the bulls. With not much else to do with a holiday weekend coming up Seth told me to head on out for the weekend.

Happy July 4th!

Pictures below.





Storm rolling in    


Momma cow and her calf cuddling    

Mrs. Dee moving the Quad cows    

Mr. Matt crop dusting    


Filming for the United Soybean Board    

Paradise    

Spraying the spiny amaranth 


Horses grazing on some fresh grass    

Ace wanting to be petted as usual