No. 153, May 1996
Spring is typically the time when many people think about alternative cropping. I usually have a big jump in the number of calls during March and April. This is a time when we can plan for production of traditional crops and get away with it, but it does not work well with specialties. Traditional crops should also be studied all year instead of spring time, but it is imperative to plan ahead for things like vegetables and high value crops.
The budget process for specialty crops is not as easy as for wheat and barley. We can usually rely on traditional crop budgets built by farmers, consultants or the Extension Service to be very accurate for you if the budget covers your economic area. Likewise, the budget will probably be very similar for your neighbor. Our production practices have evolved over a long period of time and have been fine tuned.
Budgets for specialty crops have to be based on a number of different factors such as:
We have looked at many budgets for vegetable crops and compared them to North Dakota budgets from producers. Typically the North Dakota production costs have been less, but with increasing acreage, that may or may not be the case in the future. New diseases and problems can drive costs up. Also, one producer may be using a production system geared to a lesser market that is not aiming toward high quality and would not be able to compare his budget with a farmer who grows for a grade A type market. For example, with potatoes or carrots grown for dehydration, you would budget lower than if you process and grow for a grade A or number 1 table stock market.
Each producer with a specialty crop really needs to write his or her own business budget depending on the factors mentioned above, plus many others that may be included in high value niche specialties. We can help you with budgeting and even show copies of budgets, but they are not as easy as low input traditional production planning.
Marketing specialties is very much like the budget process. For specialty crops we get closer to the market process than we do for crops commonly grown in North Dakota. One of our commercial growers tells me that he spends 60% of his production time in marketing. Typically the specialty crops that I talk about are high value, and to move toward high value means to add risk. Part of the risk comes from marketing. I have said in meetings that our first markets for vegetables are to friends and relatives. As we grow more product than we can eat, we typically give the produce away and the market is happy and even returns regardless of sizing or uniform quality. As we move to commercial markets, wholesalers, retailers, brokers, contractors and processors, we see entirely different marketing needs. These markets want service, uniformity, packaging, cooling, bar coding, transportation and a smile. These factors are only a few of the ones you may run into when marketing, but to miss out on any of them may mean loss of a sale next time.
As you market, you need to educate your buyer if you have a quality benefit or some other advantage. Quality is utmost in fresh produce marketing, for example. Test marketing is a good way to get started. Give your market some product. If everything meets their needs they will return.
When you talk to a local market they will tell you that they like local production, pricing advantage, consumer request for local product, and usually freshness. Along with things they like about local production are the negatives like poor grading, poor packing, delivery problems, short quantity and inconsistent supply. If you are aware of these factors from a recent survey, you should be better equipped to get started on a small scale with a high value specialty. As you move to commercial production your need to understand your market and that competition intensifies.
If you would like more information on marketing or budgeting give me a call. We can consult with you regarding any size of operation.
Rudy Radke,(701) 845-8528
NDSU Extension Area Ag Diversification Specialist
Water management for irrigated potatoes is a trade-off that balances higher yields from irrigation on one hand and higher input costs due to pumping expenses on the other. Too few or poorly timed irrigations compromise yield and quality, while too much irrigation adds unnecessary pumping costs and leaches nutrients from the root zone.
Based on 1992-1995 irrigation scheduling research for Russet Burbank potatoes at Oakes, we obtained maximum yields when potatoes were irrigated using a "water balance" approach similar to that found in Irrigation Scheduling by the Checkbook Method, NDSU Extension circular, AE-792. Table 1, taken from the Checkbook circular, shows how potato water use varies over the growing season. (A computer spreadsheet for the Checkbook publication has been developed -- call for more information.) For the water balance method, we applied water when the available water in the root zone was 40% depleted.
Table 1. Average potato water use (inches per day). -------------------------------------------------------- Maximum ---------- Week After Emergence -------------- Tempera- ture 1 2 3 4 5 6 7 8 -------------------------------------------------------- 50-59 F 0.02 0.03 0.04 0.05 0.07 0.08 0.08 0.08 60-69 0.03 0.04 0.08 0.09 0.11 0.13 0.14 0.14 70-79 0.04 0.06 0.09 0.12 0.15 0.17 0.19 0.19 80-89 0.05 0.08 0.12 0.16 0.19 0.22 0.25 0.25 90-99 0.06 0.10 0.14 0.19 0.24 0.27 0.30 0.30 -------------------------------------------------------- | | | 7-inch Budding Full cover -------------------------------------------------------- Maximum ---------- Week After Emergence -------------- Tempera- ture 9 10 11 12 13 14 15 -------------------------------------------------------- 50-59 F 0.08 0.08 0.08 0.07 0.06 0.05 0.04 60-69 0.14 0.13 0.13 0.12 0.10 0.09 0.07 70-79 0.19 0.19 0.18 0.17 0.14 0.12 0.10 80-89 0.25 0.24 0.23 0.21 0.18 0.16 0.13 90-99 0.30 0.29 0.29 0.26 0.23 0.19 0.16 --------------------------------------------------------
It is vital to know how much water your soil holds if irrigations are to be scheduled accurately. On average, the soil at the Oakes site has approximately 2.5 inches of water available to the plant in the top 2 feet when the soil is at field capacity. We managed a 1-foot root zone through the end of June and a 2-foot root zone for the rest of the season. In our research, we measured soil moisture weekly and corrected the water balance accordingly. The Checkbook circular recommends checking soil moisture at least every two weeks.
Irrigation water was applied in amounts ranging from 0.5 to 1.4 inch per irrigation. The smaller irrigation amounts were applied early in the season to account for the crop's shallower root zone, while the larger irrigations were applied to a more mature crop with a deeper root zone. (We also accounted for plot-to-plot variability in the soil's water-holding capacity. On a field scale, managing water for several zones within the field may or may not be possible, depending on equipment and labor availability.) We were careful to not apply more irrigation than necessary to refill the root zone of the soil. Overfilling the root zone causes the extra water to simply drain away, which does not benefit the crop but does incur extra pumping costs. We refilled the root zone to 0.1 to 0.2 inch less than field capacity to allow for small rainfalls.
In the same research, we had another set of plots to study the effect of delaying the first irrigation for potatoes. In this case, we did not irrigate until the available water was 50 to 60% depleted in the top 2 feet of the soil profile. Then we used a computer crop growth model to estimate the water available in the root zone. After the first irrigation, we irrigated when the available water in the top 2 feet of the soil profile was 40% depleted. Compared to the water balance method described above, this method resulted in no yield reduction and only a slight, nonsignificant reduction in the total, seasonal irrigation amount. A drawback we found was that it did result in potatoes with about 4% fewer #1 grade tubers.
Dean Steele,Assistant Professor, (701) 231-7268
NDSU Agricultural Engineering Department
With early planting, good management and some luck, you could produce dry bean yields of 2,500 lbs per acre or better in 1996, under irrigation.
The most immediate decision is to find high quality seed adapted to your area. Seed should be of high germination, have good vigor, no physical damage and should be dome-tested for seed-borne diseases such as blight. Another criterion is resistance or tolerance to the most prevalent bean rust races.
What about bin-run seed? The use of uncertified seed is discouraged. NDSU seed box surveys indicated yields from uncertified seed averaged 130 lbs. per acre less than from certified seed. In addition, stand establishment was 8% less.
May 12-25 is the planting window for dry bean in Minnesota and North Dakota. Beans will not germinate if planted in soils cooler than 51-52 degrees F. Plant shallow if planting early. One to 2 inches deep is ideal under most conditions.
Planting rates vary by bean class. Aim for 40-45 lbs. of pure live seed per acre for navy beans; 50-65 lbs. per acre of live seed for pintos. Target stands are 90,000 plants per acre for navies and 70,000 per acre for pintos. Slightly higher rates are recommended under irrigation or for navies planted in narrow rows. For other classes, see table below.
Dry bean seeding rates. ---------------------------------------------- Average Rate/A Rate/A Class Seeds/lb (lb) Seeds ---------------------------------------------- Black Turtle 2300 42 90000 Great Northern 1000 70 70000 Kidney 900 100 90000 Navy 2400 40 90000 Navy (6"-14" spacing) 2400 60 140000 Pink 1700 55 90000 Pinto 1350 55 70000 Small Red 1400 60 80000 Small White 3000 30 90000 ---------------------------------------------- 60 lb/bu - all dry edible beans.
Dry beans need good fertility management to reach high yield potential. Nitrogen (N) and zinc (Zn) are both key elements to obtaining 2500 lbs. plus yield. N recommendations have recently been revised. For 2500 lbs per acre yields, 125 lbs per acre of both soil and fertilizer applied N is needed.
You may wish to take advantage of the N-fixing ability of dry beans. Inoculate beans just prior to planting with the phaseoli strain of rhizobium bacteria. This practice would be particularly beneficial on land that has never been cropped to dry beans. It appears that some of the new inoculum sources have greater tolerance to seed treatments. Preliminary NDSU research showed last year that additional yield has resulted from inoculation.
Navy beans are especially responsive to zinc fertilizer and will respond to higher yields in most situations, if the micronutrient is limited. Soil test to determine levels in your field and then broadcast and incorporate Zn with other fertilizer or herbicide. Zn can be applied in a starter fertilizer, too. Reduce the Zn rates by one-third. Also, zinc can be applied as a foliar treatment during the early growth stages of dry beans.
For weed control, use both chemicals and cultivation when and if needed. Use a preplant incorporated herbicide or tank mix as a base, along with a planned backup of post-applied herbicide if tough, hard to manage weeds become a problem.
Continue to monitor the bean crop throughout the growing season. Check for diseases early, so appropriate steps can be taken to stop any disease at its inception. Use labeled fungicides when warranted and if they are economical.
Harvest beans when they are just beyond physiological maturity. Don't wait until they are too dry and mature since natural pod loss and pod shattering will result. Also, beans that are too dry (10-12% moisture) are mechanically cracked, split and checked more during the harvesting process. Combine beans when they are 16-18% moisture for best quality.
Duane Berglund,(701) 231-8135
NDSU Extension Agronomist
Potato is an intensively managed crop that is very sensitive to proper timing of field operations. Management mistakes can be very expensive. This is especially true for irrigated potatoes. Crop managers are encouraged to read as much as possible to learn about this responsive high-value crop!
Fertilization programs should be according to reasonable expected yield goals.
This article will report on a three year study of the response of four varieties to nitrogen at the Oakes Irrigated Field Trials Site. The varieties were chosen to include the two most important varieties for french fry processing, Russet Burbank and Shepody, and two promising new varieties that were being considered as suitable replacements, Goldrush and Ranger Russet. This trial had four levels of nitrogen: 75, 150, 225, and 300 lb/acre (including residual nitrogen in the top 24"). The timing of nitrogen application was: 1/3 at planting, 1/3 at emergence, 1/6 at hilling and 1/6 in late June. Soil and petiole samples were collected at 7 to 10 day intervals from late June until late August; petiole nitrate of expressed sap was determined with a hand-held Cardy Meter (Spectrum Technologies). Duplicate petiole samples from half the plots were dried and evaluated for nitrate by the NDSU Soil Testing Laboratory. Harvested potatoes were graded and evaluated for quality before sending samples to the USDA Potato Research Laboratory in East Grand Forks, MN. for processing into frozen par-fries. These par-fries were finish-fried and evaluated for color and texture at NDSU.
The nitrate-N readings from petiole sap were well correlated with the standard laboratory method of determining nitrate-N, although the meter required extreme care in calibration. A representative plot of the petiole sap nitrate-N for the different nitrogen levels is given in Figure 1. Petiole nitrate-N was high in June for almost all treatments, and then declined through July-August at differing rates for the different N treatments. Petiole nitrate-N for the different nitrogen levels was easily distinguished by early July, with the low nitrogen treatment dropping below 500 ppm in July. The excess N treatment (300 lb/acre) had high petiole nitrate-N through the month of July. These trends were evident each year, but petiole nitrate-N showed a slower decline in 1995 than in 1993 and 1994. The petiole-N content of Ranger Russet and Shepody was about 10% higher than for Russet Burbank and Goldrush on most sampling dates.
Figure 1. Average petiole nitrate of the four varieties at each of four nitrogen levels in 1994.
Yields differed each year (Figure 2). 1993 was relatively cool and wet. Soil nitrate readings remained low. Yields were somewhat lower in our test plots than in farmers' fields in 1993, but the solids content of the potatoes was very high. Conditions were excellent in 1994 and yields and quality were high. May of 1995 was cool, after which temperatures were warm and yields and average size were depressed, in spite of maintaining healthy foliage later in the season than in the previous two seasons. Only in 1993, which had several rainfall events sufficient to cause leaching was there a yield response to nitrogen rates over 150 lbs/acre for Russet Burbank and Ranger Russet. Yield decreased with the two higher nitrogen rates for these two varieties every year, and for Goldrush and Shepody in 1995. Goldrush was less affected by high nitrogen rates than the other varieties. Shepody responded to higher nitrogen rates with larger yield increases than did the other varieties.
Figure 2. Effect of nitrogen on yield of four varieties in the years 1993 to 1995.
Quality was negatively affected by nitrogen rates over 150 lb/acre. The quality determinants we use are size distribution (10 to 16 oz are most desirable), the incidence of hollow heart, knobs and growth cracks, specific gravity (a measure of the percent solids in the tuber), and fry color. The percentage of small tubers (< 4 oz) declined with increasing nitrogen up to 225 lb/acre. Specific gravity was highest in 1993, somewhat lower in 1994, and lowest in 1995. Specific gravity declined with each additional increment of nitrogen in each of the three years. Color of french fries was darker with increasing nitrogen rates for each variety. The order of the varieties with respect to both fry color and severity of dark ends was Ranger Russet (lightest), Russet Burbank, Shepody, and Goldrush (darkest). The increment of darkening with increasing nitrogen rate was greater for Goldrush and Shepody than for Ranger Russet and Russet Burbank.
Nitrogen is a management tool that can be easily supplemented according to crop needs during the course of a season. However, as this study shows, the manager should be as cautious of high nitrogen rates as of nitrogen deficiency. Excess nitrogen can reduce yield and quality, especially in a short-season location like North Dakota, and for later-maturing varieties like Russet Burbank. Differences among N treatments were visible in plots in July, and were especially obvious in August when the low nitrogen plots were maturing. These low N plots had nearly completely died down by the end of August in 1993 and 1994, when the high N plots were still green. Based on appearance of foliage in mid-August, one would have made the incorrect assumption that the high nitrogen treatments were superior to the lower N plots with their yellowing plants, and would have expected better yields in those green high-N plots. However, the data from these studies support NDSU recommendations of 140 to 180 lb/acre of total N (subtract soil N in the top 2 feet to determine the amount to be applied) for an expected crop of 350 to 450 cwt/acre (Table 1). Higher nitrogen rates should be avoided, except perhaps when high rainfall causes a steep drop in soil test nitrogen. Nitrogen rates should be further reduced when an early harvest is desired, in order to allow maturation and to maintain quality for the early harvest.
Table 1. NDSU recommendations for nitrogen requirement of irrigated potatoes. --------------------------------- Yield Goal Total Nitrogen1 --------------------------------- (cwt/acre) 200 80 300 120 400 160 500 200 --------------------------------- 1 Includes soil N in the top 2 ft. + applied N
Nitrate content of petioles declined over the period July 1 through late August. This decline is normal and should be allowed to proceed in a normal fashion through the season to allow plants to put their energy into filling tubers and minimize competition between vines and tubers. This will also lead to a more mature crop that will be easier to vine-kill and that will have superior skin set and tuber quality than a crop that had too much nitrogen.
The timing of nitrogen application is another important issue that can affect yield, quality, and leaching of applied nitrogen from the root zone of the crop. In other studies, there was no apparent benefit from spreading nitrogen applications into July, but the negative effect of excess N was more serious with a regime that spread application into late July. We plan to continue these studies on nitrogen management of irrigated potatoes in North Dakota to assist this growing segment of the North Dakota potato industry.
Bissonnette HL, Preston DA, Lamey HA. 1993. Potato Production and Pest Management in North Dakota and Minnesota. NDSU/UM Extension Bulletin 26
Dean BB. 1994. Managing the Potato Production System. Food Products Press. Binghamton, NY.
Rowe RC (editor). 1993. Potato Health Management. American Phytopathological Society. 3340 Pilot Knob Road, St. Paul. MN.
Scherer TF, Weigel J, Grabanski R, Preston DA. 1992. Growing Irrigated Potatoes. NDSU Extension Bulletin AE-1040
Jim Lorenzen,(701) 231-7404
Assistant Professor, NDSU Plant Science Dept.
The water supply for many irrigation systems is a well. Quite often the hole was bored with a rotary drilling rig and the well was constructed with anywhere from an 8 to 16 inch diameter screen and casing. Screens are made from stainless steel, regular steel, iron, and plastic. Casing materials are made from steel, iron and plastic. Wells in unconfined aquifers are commonly screened over the bottom 35% of the saturated thickness. Wells in confined aquifers are commonly screened over 80% of the confined layer. For maintenance reasons and for monitoring water levels, the well should have an access hole into the casing below the pump at least 1 inch in diameter (2 inches would be better).
The depth to static water in wells is the least in the spring (May-June) and greatest in late summer (August-September). Depth to pumping water level in a well affects the pumping rate, therefore, it is important to measure the depth to static water and to pumping water when the pump is first turned on and in middle to late August. The pumping water level should be measured after the pump has been pumping at normal capacity for at least 1 hour. Subtracting the depth to the static water level reading from the depth to pumping water level reading indicates the amount of drawdown in the well. The date of reading, the depth to static water, the depth to the pumping water level and the drawdown should be written down in a convenient place (a notebook or the inside of an electrical control panel or diesel control panel are good locations).
Recording this information each year will provide you with valuable information about the operation of your well and pump. For instance, if the static level is the same as previous years but the pumping level is greater (at the normal system flow rate) then the screen could be getting plugged. Chlorination or acid washing may be needed. If the depth to static water and drawdown stay the same as previous years, but the flow rate or pressure is reduced it may indicate that your pump impellers need adjusting or are becoming worn. If there is air in the water when pumping, either the depth to static water has increased during the season or the well screen is partially plugged. By diligently recording well water levels each year, you will see these problems developing and will have time to take care of them before they affect your irrigation system.
Tom Scherer,(701) 231-7239
NDSU Extension Agricultural Engineer
No. 153, May 1996
NDSU Extension Service, North Dakota State University of Agriculture and Applied
Science, and U.S. Department of Agriculture cooperating. Sharon D. Anderson, Director, Fargo,
North Dakota. Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914.
We offer our programs and facilities to all persons regardless of race, color, national origin,
religion, sex, disability, age, Vietnam era veterans status, or sexual orientation; and are an
equal opportunity employer.
This publication will be made available in alternative formats for people with disabilities upon request, 701/231-7881.
North Dakota State University
NDSU Extension Service