Surviving Weather Cycles In-Service Training November 9, 2006 Bob Woods, Area Extension Agronomy Specialist, NE District Although it may be true that if you don’t like the weather today, just wait for tomorrow. But actually, weather does follow some fairly consistent patterns that should be a major consideration in managing pasture and range in Northeast OK.

In Eastern Oklahoma you are always 2 weeks away from a drought. The problem is you never know when the drought begins or ends. There’s also an old saying that in Eastern OK your always 2 weeks from a drought. That is largely true not only as a consequence of our unpredictable weather but also due to some soil limitations. The Cherokee prairie soils consist have an underlying clay layer that limits effective water holding capacity to the topsoil above the clay layer that may varies from 3 feet to less that a foot. During rapid plant growth and in the summer time heat transpiration and evaporation can exhaust the moisture held in these prairie soils quite rapidly. The rocky soils in the eastern tier counties also lack adequate water holding capacity to sustain rapid summer plant growth for more than a couple of weeks without a well timed rain. Another problem with the weather is you never know when you begin or end a drought. You only know this after the fact. In other words when you know your into a drought it is too late to anything but react and that is usually accompanied with an unexpected loss in income due to, increased expenses, forced sales, reduced animal performance or a number of other unexpected consequences that reduce income.

Rainfall Comparisons 5 Counties The rainfall pattern of NE OK is described as bi modal. In other words, we have 2 seasons of higher rainfall with dry seasons in the mid summer and mid winter. With less opportunity for late summer rains, cool season perennial grasses and summer crops such as corn and soybeans are not well adapted to the Western side of the state. Wheat production is a good fit for the weather pattern of W. OK. Moisture is conserved through the summer by fallowing the ground and controlling summer vegetation, wheat is planted in the fall and normally needs a small amount of rain to germinate but once it is established may survive and grow through the fall and early spring on conserved soil moisture. The rainy season of W. Ok coincides with the grain production stage of growth when the wheat's water requirement is the greatest. In Eastern Ok as a result of our normal County fair rains, we can successfully grow the fescue and other cool season grasses even in existing bermudagrass pastures without conserving moisture we receive during the summer.

Seasonal Rainfall Comparisons 5 Counties Most who are familiar with NE OK weather would describe late summer and early fall as a dry season, but this chart shows that over a period of 30 years, late summer rainfall was almost equivalent to early summer rainfall.

Monthly rainfall patterns are fairly consistent but drought can occur in any month. Long term weather patterns have typically followed a nearly decadal pattern. Wet spell of 80’s and 90’s was unprecedented. Monthly rainfall patterns are fairly consistent but drought can occur in any month. Since 1895, wet and dry cycles followed a mostly decadal pattern until the early to mid eighties. Beginning in the 80’s, we experienced an unprecedented wet spell.

State Climatologist says “it appears we are in a dry cycle”. The state climatologist has said that it appears we have entered an extended period of below average rainfall.

Surviving Weather Cycles Weather Patterns How Weather Pattern applies to Introduced Forages Warm Season Grasses Cool Season Grasses Native Range Lifeboats In the remainder of this program we will look more closely at these rainfall patterns, when rain is most likely, and how these patterns and a prediction of less rainfall effect management decisions on introduced forages, yields and stocking rates on native range, and some things we can do to provide an adequate lifeboat as a hedge against drought.

74% > 8 inches 87% > 6 inches Average 11.23 If you consider the odds, over the past 100 years eastern Oklahoma received at least 8 inches of rainfall in the fall season (Sept 21 to Dec 21) 74% of the years. More than 6 inches 87% of the years. The average is 11 inches. 74% > 8 inches 87% > 6 inches Average 11.23

Dry Season – Average 7.16 86% > 4 inches Winter is our normal dry season but 86% of the time we receive more that 4 inches during the winter season and the average is 7 inches. Dry Season – Average 7.16 86% > 4 inches

67% > 12 inches Average 13.65 84% > 10 inches Spring is our normal wet season and 84% of the last 100 years we received more than 10 inches and averaged almost 14 inches. 67% > 12 inches Average 13.65 84% > 10 inches

Many producers probably think of summer as a dry season but we average 11 inches and have received more than 8 inches of rainfall in 77% of the summers out of the last 100 years. 77% > 8 inches Average 11.16

Long Term Avg. 43.2 inches 93% > 28 inches All totaled, E. Central Oklahoma exceeded 28 inches of annual rainfall in 93 out of 100 years from 1895 to 2005. The long term average is 43 inches. Long Term Avg. 43.2 inches 93% > 28 inches

Rainfall Expectations Fall - 6 inches (87%) Winter – 4 inches (86%) Spring – 10 inches (84%) Summer – 8 inches (77%) Total – 28 inches This review of the graphs shows the expected distribution of rainfall even if we do enter an extended dry pattern as the state climatologists suggests.

Warm Season Introduced Forages (Bermudagrass) Surviving a Dry Spell Warm Season Introduced Forages (Bermudagrass) So let’s take a look at how we can manage warm season introduced forages to take maximum advantage of limited rainfall amounts that we might experience during a drought.

Bermudagrass Water Efficiency Without fertilizer - 18 to 20 inches of water/ton With fertilizer - As little as 4 inches/ton Average Spring and Summer Rainfall for NE OK is 23.7 inches (5T/Yr) Dry Year 14 inches (3T/Yr) This slide is based on work by Burton et. Al. at Tifton Ga. Have you ever thought about why much of the bermudagrass in E. OK is harvested for hay in mid July? It’s because, without fertilizer, it requires that much time to accumulate enough tonnage to justify harvesting. When fertilized bermudagrass can use the available moisture more efficiently and a ton of production can be produced on as little as 4 inches of available moisture. In E. Ok, where we get an average of 23.7 inches of moisture in the spring and summer months, 5 tons of bermudagrass production per acre is possible. In a dry year with only 14 inches we could expect to produce 3 tons per acre assuming sufficient nitrogen is available and other plant nutrients were provided as recommended by a soil test.

Bermudagrass Yield Response to Precipitation Producers commonly resist applying fertilizer during dry weather due primarily to a concern of loosing nitrogen or spending money and not getting a response. But as this slide clearly illustrates, you can expect a response to nitrogen fertilizer even in a dry year although less than in the wet years. Burton and Hanna, 1995

Split N Effects on Bermudagrass Yield ERS, Haskell, OK 7000 lbs in a dry summer Dry Matter, T/A 200 + 200 400 As stated in an earlier slide, adequately fertilized, bermudagrass can yield about 1 ton of forage with 4 inches of water. In a dry spring and summer season, with only 14 inches of moisture, bermudagrass still has the potential to produce 3 tons per acre if fertilized with 150 pounds of actual nitrogen per acre. In 1977 and ’78 rainfall at the Eastern Research Station near Haskell was 8.76 inches and 14.33 inches below the long term average. Yet, in 1978 bermudagrass fertilized at 200 pounds of nitrogen per acre produced 7,438 pounds per acre. To achieve this yield in the dry years you must have adequate nitrogen available when moisture is available. 100 + 100 100 + 100 200 200 100 + 100 200 1978 1979 1980

Rainfall for Payne County (1971-2000) Fertilize Topdress N For optimum production and efficient use of moisture, plant nutrients must be adequate at the time moisture is available. For warm season grasses such as bermudagrass that begin rapid growth in early May fertilizer, if needed, should be applied in May and June.

YEAR-ROUND GRAZING SYSTEM Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 60% of annual rainfall 25 inches (McIntosh Co.) Cool-season Grass C.S.G. C.S.G./legume Bermuda/legume 60% of the years rainfall occurs in the summer months, explains why warm season grasses are the predominant forage base for most livestock grazing enterprises. Remember if you need to fertilize summer forage, you cannot afford to miss the rains of early summer. Another important point is that the fertilizer needs to beat the rain. In other words, if you wait for rain to fertilize you are really waiting for 2 rains. Bermuda Bermuda N.R. Native Range N.R. It rains in May and June – Don’t miss it!

Cool Season Introduced Forages (Fescue) Surviving a Dry Spell Cool Season Introduced Forages (Fescue)

Rainfall for Washington County (1971-2000) Fertilize Fertilize? Cool season grasses will begin growing in the late summer as soon as we get those “County Fair Rains”. And just as bermudagrass uses the available moisture more efficiently if fertilized, so will cool season grasses. So consider fertilizing fescue in the fall. If it does not rain, then fertilizer is already there when it’s time to apply that spring topdress application of nitrogen. A forage budget should be determined before applying fertilizer in February to avoid excess fescue in May when bermudagrass is beginning to grow. Fescue

A trial conducted near Wynona, OK in South Central Osage County, from 1975 to 1980 concluded that fertilizing fescue in the fall did not work. But now that we can look at the historical context, this was during an dry climate cycle. They reported a response to fertilization in only one out of the 5 years as indicated by the circle. During the Late 80’s and through the 90’s they would probably have reached a different conclusion. I would recommend an approach of considering subsoil moisture and watching the forecasts. Dr. Jim Stritzke, retired State Weed and Brush Control Specialist used to say that when you are bone dry it takes 2 inches of rain to put things back in motion. So, if we have a severe summer drought that depletes the subsoil moisture you might want to watch the weather forecast and hold off applying fertilizer until you see that reasonable chance of rain in the forecast. Subsoil moisture status is accessible at the agweather website. But remember waiting for a rain means waiting for 2 rains! A study near Wynona conducted 1975 – 1980 concluded that fertilizing fescue in the fall did not work.

Rainfall Changes across NE OK (1971-2000) This shows that the odds of receiving significant fall rain increases as you move northeast across the state. Chance of Success With Fall Fertilization Improves from west to east.

Rainfall for Washington County Full Season V Soybeans Depend on Late Summer Rainfall In Northeast Oklahoma we grow a lot of group V soybeans because historically this maturity group gives us the greatest yield potential. These group V soybeans will survive the hot dry weather of late summer in a vegetative stage of growth. This management system relies on late summer and fall rains to produce seed and fill the pods. I find that cattle producers are reluctant to apply fertilizer in August or September because they are afraid it might not rain. But if the farmer followed this same thought process we would not grow many soybeans in NE. OK. If a farmer will plant soybeans on the hope of fall rain why do ranchers resist fertilizing fescue in late summer?

Fall Rainfall Probability Muskogee, OK 3 month Total Aug Sep Oct 90% 80% 70% 60% 50% .67 1.11 1.53 1.97 2.46 .98 1.54 2.08 2.63 3.23 .33 .7 1.14 1.66 2.28 1.98 3.35 4.75 6.26 7.97 If you look at probabilities, Muskogee would expect to get at least 4.75 inches of rain during August September and October 70% of the time. Or there is only a 30% chance of receiving less than this amount. (I bet you can’t get those odds at the casino or in the lottery). Probability of getting at least this much rainfall

Fall Rainfall Probability Nowata, OK 3 month Total Aug Sep Oct 90% 80% 70% 60% 50% 1.19 1.72 2.21 2.69 3.2 .76 1.49 2.2 2.93 3.76 .35 .82 1.33 1.91 2.60 2.3 4.03 5.74 7.53 9.56 At Nowata, we would expect to get at least 5.75 inches of rain during August September and October 70% of the time. Or, there is only a 30% chance of receiving less than this amount. Probability of getting at least this much rainfall

Fall Fertilized Fescue 2001 Cherokee Craig Delaware Mayes Muskogee Nowata Okfuskee Ottawa Wagoner Washington Unfert. Lbs/A 865 1108 778 885 1117 659 1329 1382 723 Fertilized Lbs/A 3803 2174 2111 2281 3201 2419 3733 4520 5480 1574 Increase Lbs/A 2938 1067 1333 1396 2084 1760 2404 3138 4596 851 In 2001 several County Extension Educators participated in a survey to determine fall yield potential of fescue. The lowest response to fall fertilization was 851 pounds per acre at the Washington County site which had an exceptionally dry late summer and early fall. Rainfall at some of Mesonet sites across NE OK. August Sept Oct total Copan .99 1.7 3.02 5.8 (Washington Co.) Tahlequah 3.38 4.52 6.2 14.1 (Cherokee Co.) Haskell 2.44 2.39 6.71 11.54 (Closest to Wagoner Co. site) Miami 2.03 3.91 7.84 13.78 (Ottawa Co.) Vinita 2.75 2.94 7.55 13.24 (Craig Co.)

Rainfall for McIntosh County (1971-2000) Fertilize Warm Season Grasses Fertilize Introduced Pastures Fertilize Cool Season Grasses There are 2 to 4 key times to fertilize pastures. In May for introduced warm season grasses, in June as a topdress on warm season grasses, in August for late summer bermudagrass growth or fall fescue, and in February for spring fescue production. All fertilizer applications should be based on the amount of forage required as determined by a well thought out forage budget. Topdress Warm Season

Growth Distribution by Month This chart illustrates the growth curves for bermudagrass and fescue. The numbers represent an estimate of the percent of growth in each month. These curves correspond closely with the rainfall patterns.

Stocking Rates on Introduced Forages to Weather the Dry Years Production Capabilities on Average or Better Soil Bermudagrass – 3 tons/A Fescue – 2 tons/A 10,000 lbs/A is a reasonable potential if nitrogen does not limit response to available moisture. Nitrogen must be available when the moisture is! So, how much forage could we expect to make in the dry years. Based on those 1978 yields at the Eastern Research Station, you could reasonable expect rainfall to allow a 3 ton per acre yield from bermudagrass. The 2001 fescue survey would suggest we can achieve ½ to 1 ½ tons of fescue per acre in the fall and we have an the potential to produce 2 tons per acre in the spring. Just using the 3 tons for bermudagrass and 2 tons for fescue would suggest we have a potential of producing 10,000 pounds of forage per acre if nitrogen is not limiting while moisture is available.

Forage Requirement for a Spring Calving herd under 4 different management options This shows that a cow unit might require between 14,000 and 17,000 pounds of dry matter per year. The smaller amount is for a 1000 cow, including 20% of the heifers retained as replacements and that cows share of the bull power. The 17,000 is for the same system but retaining the steers through the stocker phase. This suggests that it would be possible to maintain a stocking rate of 1 cow unit per 1.4 to 1.7 acres. And do that in the dry years. OSU Publication E-926

Nitrogen Fertilizer needed by different Management Schemes Using Introduced Forages A/Cow Unit 10 – 14 5 4 3 2 1.5 Forage needed Tons/A .6 1.2 – 1.6 1.5 – 2 2 – 2.7 3 – 4 4 – 5.3 N req. Lbs/A 30 – 50 50 – 70 70 – 105 120 – 170 170 - 235 N req. Lbs/cow 150 – 250 200 – 280 210 – 315 240 – 340 255 - 353 A reasonably safe level is 3 acres per cow unit if relying entirely on introduced forages. This could be accomplished on as little as 105 pounds of nitrogen per acre and well within the capability of some exceptionally dry years. Reasonably Safe

Mayes County Fairgrounds Lawn Bermudagrass/Fertilizer Demo Mayes County Fairgrounds Lawn Bermudagrass/Fertilizer Demo. 1997 Fertilized May 12, Harvested August 5 So far this discussion has focused on the application of nitrogen fertilizer. But it is important to remember that P and K, and lime, should be applied as recommended by a soil test. These nutrients are critical to efficient use of the nitrogen as illustrated by this table. This are results of a demonstration on the lawn of the Mayes County Extension Office. This site fits the description of a mismanaged pasture, mowed short every week or 2, at times a parking lot, never fertilized, with an exceptionally low level of P and K. A fairly common belief is that P does not help you till the year after it is applied. A claim that this trial clearly contradicts. If the soil test recommends phosphorus you can expect a fairly rapid and within the season applied. Notice that P and K according to the soil test more than doubled the response to nitrogen up to the 200 pound per acre level. Above 200 pounds of N, moisture became the limiting factor.

Surviving a Dry Spell Native Range

Range Site Productivity McIntosh County Soil Survey - 1981 Range Site Wet Year Dry Year Claypan Prairie 4,500 2,000 Deep Sand Savannah 4,000 2,000 Loamy Prairie 7,000 4,500 Loamy Savannah 5,000 2,500 Sandy Savannah 4,600 2,800 Shallow Claypan 3,800 1,800 Shallow Prairie 3,800 1,800 Shallow Savannah 3,000 1,400 Stocking rates on native range are based on the amount of biomass produced and using a harvest efficiency of about 25 to 30%. In other words, of the 4500 pounds (wet year yield) listed for the claypan prairie, you expect grazing livestock to consume about 1350 pounds or less. Using the numbers shown earlier (cow unit needing 14,000) you could maintain a stocking rate of 1 cow per 10.3 acres in the wet years. But production in the dry years is 50% less. Stocking rates that were allowed to creep upwards during the extended wet cycle of the 80’s and 90’s means a possible shipwreck in a dry cycle. Dry year yield is as much as 50% less than a wet year

Range Site Productivity McIntosh County Soil Survey - 1981 Range Site Normal Year Dry Year Claypan Prairie 3,000 2,000 Deep Sand Savannah 2,800 2,000 Loamy Prairie 5,500 4,500 Loamy Savannah 3,500 2,500 Sandy Savannah 3,500 2,800 Shallow Claypan 2,600 1,800 Shallow Prairie 2,600 1,800 Shallow Savannah 2,000 1,400 Dry year yields are only 30% less than the normal year yields. Dry year yield is only 30% less in the dry years

Effect of Stocking Rate in a Drought Sandy Savannah Harvestable Wet year – 5000 X .3 = 1500 Normal year – 3500 X .3 = 1050 Dry Year – 2000 X .3 = 600 Stocked for the Wet year - harvest efficiency is 75% in the dry year. Stocked for the Normal year - Harvest Efficiency is 52% in the dry year. Using a sandy savannah site as the example and applying the 30% harvest efficiency rule shows harvestable yield between 1500 pounds per acre in the wet year to 600 pounds in the dry years. If stocked based on wet year production levels, the drop in yield in a dry year would mean harvesting 75% of the available biomass and have an adverse effect on both the range condition and the animal performance. If stocked for the normal years we may survive the dry year without making changes in the stocking rates and avoiding serious impacts on the pasture or livestock because the amount of biomass harvested only increased to 50%.

Dennis – Loamy Prairie, 4500 – 7000 lbs/A The message is – native pasture that is stocked for the normal year will survive the dry years without causing major changes in management. These native systems are really quite resilient and will tolerate the occasional dry year if stocked for the normal years. Native Range can tolerate some over grazing in the dry years if stocked appropriately for the normal years.

Learn to appreciate Forbs Patch Burning Burn 1/3 each year Timing is not critical Learn to appreciate Forbs Fire is still a good management tool on Native range but it might be wise to only burn about 1/3 per year to leave some standing residue as a hedge against drought. The magical number for suppressing brush is to burn every 3 years or less. Don’t Burn the whole place.

Surviving a Dry Spell Lifeboats

Lifeboat Bermudagrass and fescue fertilized ahead of the rains Native range stocked for the normal year Hay barns Store a 60 to 90 day supply With a plan to feed 30 Could store hay in good years Take advantage of lower hay prices Here are some recommendations for creating those necessary lifeboats. As illustrated earlier in the presentation – if you need to increase yields by applying fertilizer then be sure to fertilize to take advantage of anticipated rainfall. Don’t be the one that is waiting for 2 rains. Native Range stocked for the normal year will have a built in lifeboat for the dry years. And consider building adequate storage for a 60 to 90 day hay supply. But plan your grazing system for a 30 day hay supply. That’s why the old farms and ranches all had big hay barns. This would allow the flexibility to store hay in the good years when hay is cheap and store it until you need it in the dry year.

Percent Dry Matter Loss of Round Hay Bales Storage Period Storage Method Up to 9 monthsa 12 to 18 months Exposed Ground 5-20 15-50 Elevated 3-15 12-35 Covered 5-10 10-15 2-4 Under roof 2-5 3-10 Enclosed barn Less than 2 a If used before spring warm-up. Source: Huhnke. 18 45 Round bales stored outdoors should be fed in the year harvested or storage losses can become excessive. Storing can save 18% in the first year but if stored into a second year can save 45%.

Percent of Bale to Cover Payment Bale Price Single Stacked Barn Double $30 29% 18% $40 22% 13% $50 17% 11% $60 15% 9% Based on the 18% savings of the previous slide, a barn and the capability of stacking round bales 2 high would be cost effective at a bale price of 30 dollars and this improves greatly if storing in the second year or if hay is more expensive. As Roy Ball pointed out in a recent M.C. meeting, if the accountant says you need to spend some money, then a barn would be good place to spend it. $10 / sq ft cost

2000 Square Foot Barn $7 $1,220 $12.20 $8.03 $10 $1,744 $17.44 $10.78 Cost Per Sq Ft Annual Payment Single Stack Double $7 $1,220 $12.20 $8.03 $10 $1,744 $17.44 $10.78 $12 $2,092 $20.92 $12.62 This slide shows the annual payment at different costs for constructing a barn and the storage cost per bale if stacked 1 high or 2 high and includes the cost of a front end loader if stacking 2 high. 6% interest Single stack = 100 bales Front End Loader 20 years Double stack = 190 bales $3,500

Recommendations to Survive a Dry Spell? Act don’t React Moderate Stocking Rates Fertilize ahead of the rain Drought could be opportunity Wrapping up - the way to survive a dry spell is by acting in advance of a drought rather than reacting after some of the options have already “dried up”. Use moderate stocking rates, reasonable yield goals and fertilize judiciously according to a forage budget. Fertilizer ahead of the rain and not after the rain. And if you do – you might make an opportunity out of other’s misfortune. You could have hay to sell when prices are high, and extra grass when cows are cheap.

Weather Patterns are Cyclical and Drought is a Normal Occurrence Avoid a Drought Crisis by Planning for Drought Droughts and weather cycles are normal. Remember – It rains in a drought, it just rains less! So the key is have a plan for drought so we don’t find ourselves in a drought crisis.