Dealing with Droughty Pasture Conditions– Victor Shelton
Droughty conditions have greatly reduced forage availability in many parts of Indiana. First cutting hay had some reduction in yield and in most areas, no second cutting was feasible. Pastures suffered the same problems and normal production has been cut in more areas by at least forty percent from the average at this time.
If pastures have been grazed down to their minimum recommended heights and no regrowth has occurred, or grasses
appear to be completely dormant, then producers should seriously consider moving livestock to a sacrifice area and off the pastures and then feeding the livestock hay and supplements as needed. If no sacrifice area is available then temporary fence could be used to create an area. The sacrifice area should have a fresh adequate water supply and some shade for periods with extreme temperatures. When air temperatures are over 85 degrees and humidity is also 85 percent or higher, shade becomes a necessity during the heat of the day. Feeding hay is better than allowing livestock to continuously graze forages and thus severely overgraze, weakening the sward, reducing intake of the animals, and compromising most chances of any good regrowth once adequate moisture returns. Protected reserves have more potential of increased dividends of valuable forage for later on.
It is recommended that producers do an inventory of dry matter on hand and estimate livestock future and present requirements. Inventory all grazing livestock and assume at least three percent dry matter needs per body weight per day. Next walk pastures noting any potential grazing forage present and estimate the amount of available dry matter present per acre. For a rough estimate, figure 250 pounds of dry matter per average acre inch present subtracting what should be left behind. The total estimated from pasture and from hay reserves can then be weighed against livestock requirements. This is what is present now. Lastly estimate the potential fall regrowth on the conservative side for any possible stockpile or annuals.
The grazing efficiency or harvest efficiency also influences the amount of this hay or pasture that is consumed or wasted; rough figure it at 50%. This will provide an idea of how much dry matter or hay is needed or in surplus until next season. If pastures remain dormant, especially tall fescue and orchardgrass pastures, and we get sufficient rain later to plant, it might
be one of those rare opportunities to inter-seed into the existing sod with some annuals. Only very competitive annuals will come close to working because they have to stay ahead of the existing forages that will soon break dormancy. Some decent success has been achieved with one or more of winter peas, oats, turnips and cereal rye in these late summer conditions. Conditions vary a lot and there are a lot of “it depends”, but there is potential for good fall and winter growth and some
nitrogen and soil building especially from the peas. Soil fertility must be in at least moderate to good condition for optimal
growth and don’t forget to inoculate the peas or you won’t get near the nitrogen or growth possible. There is more growth
potential for late winter and spring grazing with the peas and cereal rye. Peas should not be planted on pasture that will be grazed this fall or early winter. Oats, turnips and cereal rye to some extent, can provide good forage for grazing in the fall.
Being able to graze annuals this fall, if conditions allow, will allow more time for regrowth on pastures to be utilized after the
annuals are no longer available.
Though it is not the first choice by most producers, reducing animal numbers may be one of the best options. Culling late calving or out of season calving cows, old or hard to maintain body condition score animals is a good place to start. Readily marketable animals should be next such as stocker cattle or retained heifers. Early weaning of calves can also be an option. Reducing numbers, especially if numbers are possibly excessive even for a good year, will help stretch reserves, reduce any hay or supplements needed and allow for longer rest periods. Most purchased inputs into an operation are a direct hit on the bottom line and need to be seriously contemplated before purchasing.
Watch for possible poisonous plant issues as livestock graze areas with low available forage. Poison hemlock and white snake root become increasingly more likely to be eaten as hungry livestock search for “something green”. Monitor pastures
for poisonous plants and forage amounts.
Look for possible grazing or forage harvesting options. Certainly if possible, grazing is generally more cost effective than harvesting, moving, and feeding forages to the livestock. Opportunities for grazing and forage should be looked at carefully to make sure it will meet the nutritional needs of the livestock and that it has no negative impacts. Drought stricken crops may come available to be baled, chopped or grazed. It is extremely important that the producer test all crop material for nitrates. Material with high nitrates will have to be diluted. Check herbicide withdrawals to make sure the crop can be fed to
livestock. Fall annuals planted after drought stricken corn may also be high in nitrates and should be tested prior to feeding
For pastures that are not yet dormant or have received enough rain to begin recovery, grazing instead of haying at this
time is advisable. Managed grazing of these stands may have less negative impact on the stand than haying, because it will
open up the sod less and protect valuable cover. You hear the values of soil health talked about, and here is another example.
Pastures with good cover, dry or not, maintain a cooler soil temperature than ones with poor cover. This could be the difference in whether the forage survives or not. Recently with air temperatures above 100 degrees, pastures with poor cover had soil temperatures at two inches of depth ranging from 90 to 101 degrees. Pastures with fair to good cover had soil temperatures from 74 to upper 80’s. Cooler soils, even though dry, will be better for plant revival than hotter soils and cooler
soils should also slow oxidation of valuable carbon in the soil.
Forages will do best if allowed to rest after grazing periods to allow the plant to try and replace carbohydrate reserves. Producers often panic and become increasingly afraid they are running out of forage to graze. They mistakenly open up all
the gates and let the livestock pick and choose at their will. This drastically reduces adequate rest and promotes overgrazing,
leading to weak and progressively slower responding forages. These overgrazed pastures will take much longer to recover once sufficient moisture returns, and if damage is prolonged enough, could be detrimental to the stand itself. Good productive forage stands are expensive to establish so care should be taken to prevent damage when possible. Regrowth during a drought can be very limited. Livestock should ideally be allowed to graze to the desired ideal grazing heights as outlined in the 528 Prescribed Grazing Standard. Most of our tall cool season forages which are in question would have an average “stop” grazing height of about four (4) inches. This minimum stubble height is needed to sustain the
forage plant, its root base and solar panel. The more leaf material left, generally the more roots being maintained and the quicker the response of new growth once moisture and improved conditions return.
Rotating livestock allows forages to rest between grazing periods. During drought conditions, longer rest periods are better.
If there happens to be heavier amounts of forage available, slowing the livestock down and concentrating them for very short durations will allow them to consume the best forage present, increase utilization and waste less. Allocating the forage in strips with temporary fence greatly increases control of the livestock and efficiency. During extended drought, rest periods can often exceed 60 to 90 days or more as compared to our normal 30 to 45 days during summer months. When adequate moisture is returning or present, application of 30 to 40 lbs/ac of nitrogen may help break dormancy and
boost fall growth. Diammonium phosphate (DAP), 18-46-0, is a little more stable than other forms of nitrogen and would also provide extra phosphorus. Urea, 46-0-0, would also be usable, but good moisture and cooler temperatures should be present to slow volatilization.
Additional information can be found at
http://www.in.nrcs.usda.gov/technical/Coping_With_%20A_Short_Forage_Supply_2012.pdf on forages for livestock and
http://www.extension.purdue.edu/dairy/forage/ForageNitrate2012.pdf for information on dealing with nitrates destined