USING RESERVE HERD DAYS IN ROTATIONAL STOCKING R.L. Dalrymple Agronomist And Special Projects Coordinator Rotational stocking (grazing) units range from very low paddock num bers to the very high paddock numbers and from the very basic managed to the very highly managed unit. In vir tually all units the managers have some form of management style and guidelines. In the last issue of The Forage Leader, I mentioned the use of a technique “Reserve Herd Days” which is a technique that provides management guidelines for the graz ing unit managers. We will discuss that technique in more detail in this is sue. Many years ago, as we managed grazing units for ourselves and con sulted with others (often by phone or letter), we needed a technique to judge forage reserves (availability), forage flow and other things. The technique needed to be quick, easy, grazier friendly, sufficiently accurate and easy to determine in the field or in a conversation over the phone. Thus, the RHD technique evolved for us. We have successfully used the RHD technique to help manage forage and livestock on the Controlled Rotational Grazing Unit near Ardmore for many years. Hopefully this information will make some sense and be helpful to other graziers, consultants and re searchers. Reserve Herd Days (RHD) is a measurement in days of reserve forage for a given herd of livestock on the acreage in consideration. The basic purpose is to determine the days of forage reserve (availability) for a par ticular herd on a particular area of for age at a given time. The rest of this ar ticle will illustrate some of the various reasons and functions for RHD. It has been said, “A person must measure in order to manage.” RHD is HAY STORAGE SOLUTIONS SdUARE BALE TUBER • FASTER THAN WRAPPING • 1 MAN OPERATION • HEAVIER PLASTIC THAN WRAP • HIGH MOISTURE STORAGE INTERSTATE DAIRY EQUIPMENT ac-aae FLEX-A-TUBER" THURMONT, MD 1-800-332-6559 301-271-7344 a measurement and the readings of that measurement are used to make grazing and livestock management de cisions. The readings must be used to be useful. And, when the long-term RHD parameters of a given unit are known, the future readings for years to come have more meaning. RHD can be determined for any unit It is much easier to tally the in formation in a rotation ally stocked unit than a continuously stocked unit. It is simply easier to tally RHD from individual smaller paddocks than on a relatively large single paddock. RHD is also more easily determined by the usual manager, rather than a stranger to the unit The manager has experi ence on the unit as an observer and can more easily and accurately determine the RHD based upon that experience of how fast the herd utilizes given paddock forages, etc. But, anyone can do it. There are several methods to make the RHD determinations: (1) visual. (2) calculated, and (3) measured. The grazier will commonly use the visual method of RHD readings be cause it is the quickest and easiest. They can quickly observe the accur acy of the estimate by frequent moni toring of the unit and they can update it immediately any day. Consultants and researchers often use the calcu lated or measured procedure and I of ten use all three estimates in an effort to counter check and be more accur ate. It is good for the grazier to learn all techniques to better understand the dynamics of forage and stock relation ships. With experience any procedure is adequately accurate for practicing grazier use. Determining RHA by the visual method is simply done by estimating the days the held can graze on each paddock to be used. There is no con sideration to whether the forage is property recovered, just what is graze able that day. One simply asks the ROUND BALE TUBER • MOTORIZED MACHINES • REMOTE CONTROL • EXCELLENT FOR DRY STORAGE • CALL FOR CUSTOM RATES Foraging Around, Lancaster Farming, Saturday, February 7, 1995-Page Date: May 10,1997 Paddock No. RHD Notes 1 i “ 2 3 3 ‘/a 4 0 Just used 5 ~T~ 6 2 7 5 § IQ Could hay Total 28.5 Excellent reserve for now Table 1 question. “How many days can my livestock graze here?” Then comes an answer. Of course, the type of grazing is considered in that thought full use, top-grazing, etc. For example, let’s use an eight-pad dock unit and make visual readings of RHD. Do not fret about acres and Hints On population should be in the range of 1.2 to I.S million seeds per acre, or 28 to 34 plants/square foot. This requires a planting rate of 96 pounds/acte (3 bushels per acre). Cut die seed rate of oats to VA bushels if under-seeded with a legume. • Plant a good variety. The results of this year’s variety demonstration plot are enclosed along with several yield results from Penn State Trials. It is interesting to see how well the varieties Armor, Hercules and Qgle did when compared to some of the newer varieties. Generally, pick the highest yielding varieties available from your seed supplier. • Plant with fertility. The typical fertilizer application on the pound per acre bases for for 80 bushel yield of oats would be DAP at ISO, urea at 135; and potash at 200. This mix would provide 89 pounds N, 69 pounds of PjO,, and 122 pounds of K 2 O. A complete fertilizer like this is best for spring oats. If manure was spread in the field for several years, there may not be any need for addi tional nitrogen. The fertilizer can be placed on through the drill or bulked on before planting. With low fertility number of livestock for now. In this case, the herd is there and the grazing experience is a guide to the readings. I usually list these readings in my pas ture notebook or on a form. (See Table 1.) This method is very grazier friend (Turn to Page 22) Growing Spring Oats (Continued from Page 20) levels in the field, apply the necessary fertilizer that is needed for the de veloping new oat plants. • Weed control. In oats planted alone without a legume, under-seed ing then controlling the broadleaf weeds such as ragweed is important for maximum oat yields. Stinger, Peak, MCPA, Harmony Extra, Buc tril, Bronate, Banvel and 2,4-D arc all labeled for spring oats. Take care dur ing the year previous to planting oats in a field that the amounts of trizine herbicides arc kept to a minimum or use a substitute herbicide with no car ry over potential. • Insect control. The control of damaging insects is usually not needed in most years in oat produc tion. Cereal leaf beetles can be a prob lem some years, but many common insecticides will control them. • Disease control. This is not usual ly a concern to spring oat producers. However, oat diseases are a major fac tor in oat production and losses from diseases can be higher in oats than in the other small grains. Using improved varieties with good disease resistance has prevented the losses from the diseases that plague oats. Crop rotation is the other means of controlling diseases in oats. Oats should not be planted back into a field for at least three years after the last oat crop in that field to prevent losses by diseases. 213
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