Utilizing Water Conservation and Infiltration for Black Walnut Production

PROJECT BACKGROUND I currently co-own 212 acres with my parents, Vern and Myrtle Gieseke, and I have farmed 50 acres of it for the last seven years. I am currently employed full-time as the manager for the Carver Soil and Water Conservation District in Waconia, MN, but I plan on diversifying the farming operation and eventually farm the remaining acres. (The remaining acres are currently rented by two neighboring farmers.) Of the 50 acres, I have a corn and soybean rotation on 45 acres; 3 acres in the USDA Continuous Conservation Reserve Program (CCRP) stream buffer program and 1.5 acres of black walnut seedlings and one-fourth acre of 150 wine quality grape vines. I am involved with the USDA Environmental Quality Incentives Program (EQIP) program with the manure/nutrient management and residue management programs. In the seven years I have incorporated chisel plowing and planter row cleaners to maintain crop residue of 65% after planting soybeans and 30% after planting corn. I utilize my neighbors hog manure through soil tests and manure analysis and have it injected at a rate for crop needs. I continue to add to the conservation on the farm, and I have installed a pond in the last year to collect and infiltrate crop field runoff. PROJECT DESCRIPTION AND RESULTS The goals of this project were to provide an alternate cropping system that incorporates a longer term production crop, provides farmers an opportunity to invest for their retirements, offers a different labor time frame requirement, reduces runoff and soil erosion from susceptible fields, requires a relatively small amount of acreage in comparison to the entire operation, and introduces and demonstrates the similar production concepts to agroforestry in comparison to traditional, annual row crop production. To achieve these goals, I planted a stand of genetically superior black walnut trees primarily for wood production and secondarily for nut production. The seedlings were purchased from a few sources varying in genetics and price. The 2-acre site for this project contains slopes of 6-15 per cent and soils of silty clay loam. To capture precipitation, I also incorporated a contour curb system to intercept hillside runoff and direct this runoff into a pea rock weir system to promote infiltration, To reduce summer season labor, I installed weed barrier tree mats, and I utilized vented tree tubes to promote faster growth, The vents provide the tree tubes with hardening off capabilities. The small earthen curbs were installed on the contour approximately 20-25 feet apart. The hillside was chisel plowed on the contour in November 2002 to break up the sod. The curbs were constructed using a small pull-type road grader to about 12-18 inches in height. The pea rock weir system consists of a 9-inch diameter hole, 24-30 inches deep and placed on the up-hill side of the curb. The holes were placed in between every other tree seedling. Each tree seedling then shares an infiltration hole with one other tree. The intent was to capture as much runoff as possible and infiltrate it into the hillside. Black walnuts prefer precipitation if about 35 inches a year. With this system of collection and infiltration, our average rainfall of 29 inches could be enhanced. I also augered each hole to plant the walnut seedlings to ensure that competition or hardpan would not restrict root growth. Between the rows, I intended to plant a legume to provide for a higher value crop than the grasses currently grown on the hillside, as well as provide a nitrogen source for the walnuts. Due to time constraints and consistent precipitations during May and June, I was not able to interplant clover into the hillside. I did purchase the seed and will attempt to interseed next spring. To provide additional nutrients to the seedlings, hog manure was injected into the sod hillside the previous fall. This was done due to the positive results of the first three years growth of black walnut seedlings planted in Missouri and fertilized with chicken manure (this work was documented by SW Mo RC&D, Upper Shoal Creek, Subgrant #G96-NPS-03). The intent of the contour curbs was also to capture any nutrient runoff and allow it to be incorporated into the root zone via the pea rock weirs. The design of this system was a compilation of reading and research of agroforestry articles and information. This system is also a hybrid of research the Carver Soil & Water Conservation District conducted on retrofitting open inlets with rock inlets. The rock inlet design was borrowed from Morriem Drainage of Freeborn County, Minnesota. Phil Morriem was previously a conservation district employee in the 1960’s. My interest in providing longer term crops on the farm and my interest in agroforestry along with conservation led me to this design. My wife and I attended an agroforestry tour that included a visit to Bagersett Farms in southeast Minnesota. Discussions at the tour with Bagersett Farm staff, Dean Current, U of Minnesota Center for Integrated Natural Resources and Agricultural Management and Bruce Wright, Natural Resources Conservation Service (NRCS) also contributed to adjustments in the implementation of the grant activity. Several publications from the U of Missouri Center for Agroforestry UMCA-1-2000, UMCA-2-2001, UMCA-3-2001. The ultimate results of this project are in the long-term economics of harvesting black walnut timber. The shorter-term results include the harvest-worthy material from between the rows of walnuts and of the harvest of the hillside before the walnuts were planted. This year only one cutting was taken off the hillside due to a proportion being graded this spring and the initial reluctance of the neighbor who normally harvests the hay to drive haying equipment between the rows. I informed him that he should harvest the entire hill, but I was not on site when he cut the hay. I believe it was the unusual local practice of agroforestry that caused him to hesitate and not harvest the hay between the rows. The crop of hay that was harvested did not appear limited in any way due to seedlings. Grow of the grasses were actually more vigorous, which was probably due to the hog manure that was incorporated in that fall of 2002. The result I found the most interesting in the short term was the effect the contour curbs and pea rock weirs had on the runoff. In late May, when some of the contour curbs and pea rock weirs were being installed, we had a short duration rainstorm of one-half inch. This event occurred within 15 minutes. After the rain stopped, I photographed the contours that had been completed and those under construction. Those that were completed, that is, the curb established and pea rock weirs installed allowed the runoff to infiltrate and had no surface ponding. The contour curbs that were under construction, that is, had a contour curb established and had the pea rock weir holes drilled, but did not have the pea rock installed, showed runoff that would have occurred as well as water ponding that would have infiltrated into the pea rock weirs. The precipitation that occurred during May, June and early July was above normal and we experienced very little precipitation the rest of the summer. I believe the increased infiltration, especially during intense rainstorms, and the weed barrier fabric contributed to the lessened drought stress that seedlings would normally have experienced this year. Implementing a project such as this provides an avenue to sense the long-term impacts and benefits of agroforestry. Designing cropping systems that can literally go beyond one’s lifespan is a humbling experience. So much planning and good decisions must be made for the project to be ultimately successful. This, in itself, may be a significant reason a producer, or even a resident of a community would hesitate to pursue agroforestry. Any lack of confidence in this type of long-term venture would cause farmers, not familiar with that type of cropping systems to not pursue for fear of perennial failure. This lesson will provide me and other I discuss this with, with a deepened interest in seeking out the best available research, technology and experience. If I were to do it over again, I would not change any of the major structural components of the project, at this point of reflection anyway. The tree layout is aesthetically pleasing and functions as a runoff collection system, Selecting tree genetics and suppliers were difficult decisions, and in that I would go with those with a long history of growing, crossing, and cloning tree stick. The contour curbs did function as well as I had hoped and hopefully they will remain structurally intact. The contour curbs were not engineered, as with compacted clay soils. This would have defeated the purpose of providing infiltration. Instead they were design with simple road grader that turned the sod over and topped that with topsoil. The structure component of the curbs became of reestablishment of the grasses and the sod. OUTREACH Gary Hachfield, Nicollet County Extension Service, provide outreach support by utilizing their media contacts for news releases. Several newspapers, ag related magazines and local television stations were sent the information. The field demonstration day was held on July 9, 2003 from 9 a.m. to 11:30. It rained from dawn until late morning and the attendance was disappointing. A farmer that read about it in the Land Magazine attended, the manager of the Nicollet County Soil and Water Conservation District attended, and several neighboring farmers. I had a photographic poster showing the steps in the construction of the project. The walnut tree seedling stand on the hillside is readily seen from the road, and this visual display has provided as much or more dialogue about the project throughout the summer than the day of the field demonstration. This social aspect has been interesting as I have had several neighbors say that it was a good idea to do the project and then they even state a piece of their ground that they could just as well do something like that on. My family is soon to move to this property, and as a new community member again, this will provide further outreach. The social aspect, in the acceptance of how farming can be conducted, is so strong in many communities. The outcome of the outreach activities can be hard to quantify. But with a visually located project, or one that is visited often, the results can be measured in 2 to 5 years. I do believe that because of this planting, others in the community will consider tree plantings for a variety of reasons, and some will consider it for part of their long-term economic strategy. PROGRAM EVALUATION I felt the producer grant program to be manageable in the time commitment and the level of oversight provided by SARE. I cannot provide any suggestions for change to the regional Administrative Council at this time.