Effects of Late-Season Water Lease on Forage Crops

Effects of Late-Season Water Lease on Forage Crops

Summary

The Dry Cottonwood Creek Ranch and MSU Extension are investigating the effects of split-season water

leases on hay crops in the Deer Lodge valley of western Montana. The specific purpose is to analyze the

agronomic and economic benefits and impacts of a split-season water lease on forage crops over several

years under ranch conditions.

The project was initiated in May of 2013. Two AM400 soil moisture monitoring recorders from MK Hansen Co. in Wenatchee, Washington were ordered and put in place. Each monitor was connected to four probes (block type), 500 ft. of CAT3 telephone wire, wire nut connectors, and two special tools for stripping the small wire and connecting it to the monitor were purchased. The probes were installed on June 25/26, 2013 on two ranches, Dry Cottonwood Creek Ranch (DCCR) and Lampert Ranch, all in alfalfa fields. One of the probes was moved from Dry Cottonwood Ranch in 2015 to the 2 Bar Ranch.  The paired fields in each ranch were planted with the same variety in the same year. Soil moisture was measured at “deep” and “shallow” levels, one probe being at 30″ deep and and one probe at a 12″ depth, packed in with moist soil and water. Probe wires were trenched into place. Software for these probes was obtained in the spring of 2014 and has been utilized since for processing the soil moisture data.

Lampert Ranch-

Soil probes logged data at two locations in Varney Sandy Clay Loam, one irrigated and one non-irrigated (late season). Each location contained two probes, which were buried at depths of one and three feet. The Lampert Ranch soil data demonstrates lower soil tension (wetter) in the irrigated field. For both fields, the deep probe was highly saturated with water throughout the irrigation season, which suggests an abnormally high groundwater table. The soil moisture tension for the shallow probes was also higher (drier) than anticipated. Irrigation use stopped on 58 acres July 8th through September 25th of 2013 and 2014 and the acreage was decreased in 2015 to 6.6 acres. No change in water application occurred before July 8th or after September 25th.

Crop yields between the irrigated and non-irrigated acres on the Lampert Ranch only varied by .5 tons per acres.  This is quite likely because of the relatively high groundwater table that the alfalfa roots are likely accessing. 

On the Lampert ranch there was no noticeable increase in pests. Dry Cottonwood Ranch did see an increase in the Columbia Ground Squirrel, as a result from switching from flood irrigation to pivot.

Soil testing occurred in each of the irrigated fields at DCCR and analyzed for organic matter, phosphorus,

potassium, magnesium, calcium, soil PH and nitrates. Overall, soil nutrients were within normal ranges of

healthy, although some inputs of additional nitrogen and phosphorus are needed in the north field. Dry Cottonwood planted a cover crop in this field in 2015 with the intent of improving the nitrogen and phosphorus levels.

Dry Cottonwood Ranch (DCCR)-

The original probes from the East field had to be removed due to Columbian Ground Squirrel activity and the severing of wires to the probes. These probes were put in the DCCR North field. Soil probes logged data at two locations, one irrigated and one non-irrigated (late season) in 2013 and 2014. Each location contained two probes, which were buried at depths of one and three feet. The range in soil moisture tension was not as large as the Lampert Ranch between the shallow and deep probes. In addition, the irrigated shallow probe maintained high soil moisture as a result of irrigation.  In 2015, due to the need to plow the field to plant a cover crop to improve soil health in the North field, a decision was made to move the probes again to the 2 Bar Ranch.

Soil moisture measurements were still conducted using the feel and appearance method and recorded using the NRCS checkbook approach, which compares soil moisture to irrigation application, evapotranspiration and precipitation.  Due to poor water availability and little precipitation, soil moisture in the corners of the fields was low and subsequently production was quite low (not even cut, less than .5 tons per acre).  Weeds issues persisted in these non-irrigated corners.  Yields were also lower in the irrigated fields due to cover crops, aging alfalfa stands and low soil moisture at times.  With so many factors at play with DCCR in 2015, it is difficult to draw many conclusions regarding the impacts of split-season water leasing.  Cover crops such as the one planted at DCCR in 2015 did require less irrigation application overall and may not have required late season water.  For ranches looking to improve soil health, decreasing or stopping irrigation of cover crops in mid to late July could be an option for those also looking to conserve irrigation water. 

2 Bar Ranch-

The 2 Bar Ranch was chosen in 2015 due to the irrigated crop types (alfalfa) and to provide a diversity in both soil type and age of the alfalfa stand.  The alfalfa stand was replanted relatively recently (4 years) and the partially irrigated ground was located on Carten Wetsand complex soils, while the fully irrigated comparison was located on Gregson loam soils.  The two soil moisture probes were redeployed in the area irrigated after July 1 and the area that was not irrigated following first cutting on July 1. The difference in second crop yields between the irrigated and non-irrigated alfafa was .8 tons per acre.  The second crop of alfalfa was cut around the third week of August. 

The non-irrigated alfalfa was visibly drier, although there was no noticeable increase in weeds or impact to plant health.  It is also quite possible due to the soil type and vicinity to the Racetrack Creek water source that the alfalfa benefits from a high water table and adjacent irrigation.  Carten Wetsand complex soils are described as being often sub-irrigated and have poor drainage properties.  The soil moisture probe data also indicates that despite a lack of irrigation beginning July 1, soil moisture did not depart from the irrigated field until late July, indicating that the roots continued to have sufficient soil moisture for nearly 4 weeks following 1^st cutting.  The difference of .8 tons per acre in 2^nd cutting yield may have also been greater if the age of the alfalfa stand in the irrigated area was replanted at the same time.  The full season irrigated area alfalfa, which we used for comparison was predominately planted around 8 years ago.   Overall, the non-irrigated area from July 1 onward was visibly drier at the time of cutting, despite producing only a .8 ton per acre difference (2.6 ton per acre irrigated, 1.8 ton per acre non-irrigated). 

Economics

Lampert Ranch-

The compensation for the split water lease in 2013 and 2014 was through the Columbia Basin Water

Transactions Program (CBWTP) and by the SARE grant in 2015.  The lease price was determined based on the replacement cost for the second cutting of $150 per ton for alfalfa and $125 per ton for grass hay, minus the electrical input and harvesting costs. The agreed upon lease price for these 41 acres of alfalfa and 17 acres of grass hay was $76 per acre or approximately $4,400 in lost production for 2013 and 2014.  In 2015, the same price of $76 per acre was utilized, however only 6.6 acres participated in a split season water lease at a cost of $501.60.  The reason for the reduced acreage was due to budget limitations and landowner interest.    

Dry Cottonwood Ranch-

The Dry Cottonwood Ranch received $146,894 in 2014 towards the installation of a more efficient irrigation system from NRCS and the CBWTP.  An additional $80,000 in grant funds is still pending from the State of Montana Natural Resource Damage Program. This system will allow the ranch to conserve water on the previously flood irrigated acres and perform a permanent split season lease on 6.52 acres in the corners of the fields. These corners will continue to be flood irrigated up until July 1 of each year from Dry Cottonwood Creek. The payments received in 2014 went directly into the pivot purchase costs necessary to justify this long term project. In prior years, where payments were received for lost production under typical flood irrigation practices, there was a benefit according to the ranch manager at DCCR of reducing labor costs, equipment use and having capital to purchase hay as needed. During milder winters, in which the ranch incurred lower feeding requirements the costs of purchasing hay were lower and it was possible to incur surplus revenue from the water lease payments.

Due to insufficient irrigation to flood the corners in 2015, a split season lease arrangement with Dry Cottonwood Ranch was not possible.  In addition, the acres under the newly installed pivots were undergoing a cover crop experiment to improve soil health and a split season lease arrangement was not possible.  No funding was requested or disbursed, although soil moisture was tracked in the irrigated fields using the NRCS checkbook approach and plant health was observed in the non-irrigated corners.

2 Bar Ranch-

The compensation for the 2 Bar Ranch for not irrigating past July 1 was $150 for approximately 1 acre of 4 year old alfalfa irrigated via hand lines.  The rate of compensation was calculated at a slightly higher level than other properties (on a per acre basis) based on a higher projected loss in yield.  The actual loss in yield was .8 tons per acre from second cutting.  The estimated replacement cost for the loss in production was $187.50 per ton of premium alfalfa hay.  If future participation from the landowner can be secured, we will continue to monitor changes in second cutting crop yield on this property.  Although there is not a significant power savings by not irrigating this 1 acre of hand lines that is part of a much larger irrigation system served by a single pump, there is likely a labor savings.   

Johnston 2015 Soil Moisture Lampert 2015 Soil Moisture

Lampert 2015 Soil Moisture

Objectives/Performance Targets

1) Demonstrate split-season water leasing on 2 ranches in the Deer Lodge valley with 3 other cooperating

producers for further study, and develop outreach programs that promote this tool, and bring together

agricultural producers to evaluate the agronomic and economic viability of split-season water leasing.

2) Evaluate the agronomic effect, over time, of withholding irrigation water from hay crops (alfalfa and grass hay) for two months at the end of irrigation season (late July to early September).

3) Evaluate the economic effects of split-season leasing on hay production and production costs under various scenarios, considering lease prices as a variable.

Accomplishments/Milestones

General reactions from Split-Season Leasing

So far the overall reaction from the Ranches participating has been generally positive. The primary benefits include diversified income, labor savings, reduced equipment and power costs (in sprinkler irrigation situations). It also appears that split-season leases are better suited for certain acres. We have found that those acres producing low yields (possibly as a result of poor soils) and acres served by costly and inefficient irrigation systems are some of the best suited.  In addition, fields that benefit from sub-irrigation or high groundwater tables are also well suited because the relative yield impact of reducing irrigation applications can be relatively minor for second cutting.  Aging alfalfa stands and fields needing cover crops are also well suited for this type of split-season lease arrangement.

Lessons learned (so far)

The vastly different soil moisture result from the three ranches indicates that soil moisture depends a great deal on the soil type and topography. The Lampert and Dry Cottonwood ranches within this study were located just 3 miles apart and were irrigated with similar regularity; however the ability of the soil to retain moisture during a split-season lease depended on the soil type profile. As expected, soil moisture decreased without the presence of irrigation and crop yields also decreased, although some yields were still obtained due to carryover moisture and precipitation (.25-.5 ton/acre).  The 2 Bar Ranch exhibited results to the Dry Cottonwood Ranch, where soil moisture was retained in the non-irrigated areas for 2-3 weeks before we saw a departure from the irrigated areas.  Yields were slightly higher on the 2 Bar Ranch likely due to a younger alfalfa crop, potential access to an elevated groundwater table and a soil type that was more advantageous to retaining moisture. 

Further research is needed to better understand how different crop types respond to the absence of late season irrigation. Alfalfa appears to withstand drought conditions without any noticeable die off or patchiness, although only three years of split-season lease have been observed so far. Some die off has occurred on the Dry Cottonwood Ranch, although this appears to be primarily a result of the age of the alfalfa stand. More test cases are needed before any definitive conclusions can be made regarding the increase in pests or weeds. Dry Cottonwood Ranch observed an increase in both, while the Lampert and 2 Bar Ranch noticed no change in either pests or weeds. Other factors such as increased vehicles presence, earth moving activities and the installation of center pivots may have contributed to increasing gopher and weed numbers on Dry Cottonwood Ranch. These factors may need to be weighted in the economics of split-season leasing if they in fact do increase.

Closely monitoring soil moisture did help improve the application of irrigation water for optimal crop growth on Dry Cottonwood Ranch. By tracking available soil moisture through precipitation, irrigation amounts and evapotranspiration using the NRCS Checkbook approach, the Dry Cottonwood Ranch was able to optimize irrigation application. Only the necessary irrigation water was applied in order to reduce power costs and optimize plant growth. By being closely involved in the tracking of soil moisture, Dry Cottonwood Ranch gained a much better understanding of how to conserve irrigation water, improve yields and save money. In addition, the labor saved was utilized in other much needed areas of the ranching operation.  In 2015, the Dry Cottonwood Ranch also experimented with a cover crop to improve soil health and less irrigation water was required in this north field than typically required as well.  In summary, split-season leasing on certain acres appears to be a generally positive and economically beneficial arrangement for the participating ranches. Further research will assist in better defining the types of ranches that benefit the most as well as specific crop types that may be best suited for temporary split-season leases.

Impacts and Contributions/Outcomes

Dry Cottonwood Ranch-

In past years, crop yields for second cutting non-irrigated alfalfa on Dry Cottonwood were approximately .25 tons per acres. These non-irrigated areas were not cut due to the stunted growth and excessive steminess and were instead left standing for fall cattle grazing. In 2014, irrigated alfalfa for first cutting weighed in at 2.24 tons/acres and second cutting weighed in at 1.61 tons/acre for a total of 3.85 tons/acre.  In 2015, first cutting yields were down to 1.7 tons/acre and second cutting was 1.0 tons/acre for a total of 2.7 tons per acre.  2015 yields were lower due to drought conditions, aging alfafa and mechanical issues with the pivots.  In addition to the lack of water on the non-irrigated acres, the alfalfa was also reaching the end of its productive life, which may have also contributed towards a lower yield.

Lampert Ranch-

The yield of .5 tons per acre for the Lampert Ranch was consistent with prior low precipitation years for this aging alfalfa stand on well drained, sandy soils.

2 Bar Ranch-

First cutting yields were 3.5 tons per acre and second cutting yields were 1.8 tons per acre for a total of 5.3 tons per acre in 2015.  The 2 Bar Ranch exhibited much higher yields that other participants, which may have also resulted in a slightly higher loss per ton (.8 tons per acre) on the non-irrigated field.  The main lesson learned so far from the 2 Bar Ranch is that even on highly productive soils, the impacts of split season leasing on yield are not as significant as expected (.8 tons per acre less than irrigated 2^nd crop). 

2013 Clipping Data

The West field of DCCR had a total of 2550 grams between the 3 plots for an average of 850 grams. The East field of DCCR had a total of 2265 grams between the 3 plots with an average of 755 grams.

Lampert Ranch fields are alfalfa grass stands that are 4 years old. Wheel line field had a total of 2145 grams between 2 plots with an average of 1072.5 grams. Pivot Field of Lampert Ranch had a total of 2795 grams between 3 plots with an average of 932 grams.

A second clipping was not done on the DCCR as there was a miscommunication and 2nd cutting had already been taken off the field.

On August 26th a second clipping was taken on the Lampert Ranch, the wheel line field had a total of 990

grams from 2 plots with an average of 495 grams. Irrigation had ceased on this field on July 5. The field had a very healthy stand with an average temperature of 81 degrees Fahrenheit and rainfall for July was 1.42 inches and August was 1.46 inches of rainfall. The pivot field had a total of 1090 grams from 2 plots with an average of 545 grams.

2014 Clipping Data

The West field of DCCR had a total of 2810 grams between the 3 plots for an average of 937 grams. The East field of DCCR had a total of 2750 grams between the 3 plots with an average of 917 grams. This is an increase over last year partly due to more even water application by the new pivots.

On September 3, 2014 a second clipping was taken on the DCCR, the west field had at total of 1725 grams with an average of 575 grams. The East field had a total of 1710 grams with an average of 570 grams.

Lampert Ranch fields are alfalfa grass stands that are 5 years old, starting to see an encroachment of

quackgrass, Kentucky bluegrass and dandelions especially under the pivot.

Wheel line field had a total of 1725 between 2 plots with an average of 862.5 grams. Pivot Field of Lampert Ranch had a total of 2200 grams between 3 plots with an average of 733 grams. This is down overall from last year mostly attributed to grass encroachment and a cool spring.

On August 20th a second clipping was taken on the Lampert Ranch, the wheel line field had a total of 2115 grams from 2 plots with an average of 1057 grams. Irrigation had ceased on this field on July 8. The field had a very healthy stand with an average temperature of 80 degrees Fahrenheit and rainfall for July was 1.67 inches and August was 1.29 inches of rainfall. The pivot field had a total of 2430 grams from 3 plots with an average of 810 grams.

2015 Clipping Data

Only one set of clipping data was taken this year because of a mis-communication with the other grant coordinator. Clippings were taken on August 18, 2015.

Lampert Ranch fields are alfalfa grass stands that are 6 years old and another field the west field that as added with a stand that is at least 10 plus years old. Fields are getting more grass encroachment and dandelions. Wheel line field that had water turned off on July 8 had 970 grams total with an average of 485 grams per plot. The stand under the pivot had a total of 1275 grams with an average of 637.5 grams. Overall production is down due to Kentucky bluegrass and dandelion encroachment and aging of alfalfa plants with less production.

We put in another field at the Lamperts for the study which is the East field below the house. Irrigation ceased on half of the field on July 8 as well. Non-irrigated portion averaged 685 grams and irrigated portion had 805 grams of forage.

DCCR is becoming increasing harder to monitor because of change in irrigation from flood to pivot and they are not turning any water off and some of the corners receive no irrigation at all. I did do a comparison in the south field which has been done before. With the dry corner that is under flood and had not received any water this season at 460 grams and then the field under pivot was at 880 grams. This originally was the West field in other data that has been taken in the past. The dry corner in the North field was a very old stand of alfalfa grass and had 780 grams and I did not take any clippings under the pivot as it was under a cover crop.

Evan Johnston ranch I did not do any clipping data as he had already hayed.

Lampert East field, 2nd cutting 2015, no irrigation

Lampert East field. 2nd cutting no irrigation

Soil probe monitor

2013-14-15 alfalfa clipping data

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