OM = % soil organic matter YG = yield goal T / A = tons forage produced per acre CD/ A = cow days per acre NITROGEN RECOMMENDA TIONS FOR MFA FORAGF~

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1 NITROGEN RECOMMENDA TIONS FOR MFA FORAGF~ CroQ- N Recommendation (lbs./acre) season grass season grass season grass season grass stockpile Fescue seed production Warm season perennial grass Warm season perennial grass Warm season perennial grass Bluegrass Bermudagrass Bermudagrass Warm season annual grass Warm season annual grass Alt"alfa Alfalfa or Overseeding legumes Clover/grass Clover/grass Clover/grass Birdsfoot trefoivgrass Birdsfoot trefoil/grass Lespedeza/ grass Lespedeza/grass Lespedeza/grass 40 YG (T/A) x 40 YG (CD/ A) x YG (T/A) x 35 YG (CD/ A) x 0.6 YG (CD/A) x 0.6 YG (T/A) x 50 YG (CD/A) x 0.6 YG (T/A) x 40 YG (CD/ A) x 0.6 If OM < 2 = 30 If OM > 2 = 20, If OM < 2 = 30 If OM > 2 = 20, If OM < 2 = 30 If OM > 2 = 20, If OM < 2 = 30 If OM > 2 = 20, OM = % soil organic matter YG = yield goal T / A = tons forage produced per acre CD/ A = cow days per acre

2 PHOSPHORUS (P2O5 RECOMMENDATIONS FOR MFA FORAGES 1 Will require Bray 1 P (Pl) expressed as lbs./acre. uses ppm, then that number must be multiplied by 2 If lab 2) If soil PI level is less than optimum (X,j), then: P20S recommendation = P20S removal + P20S buildup 3 If soil PI level is within the optimum range, P20S recommendation = P20S removal then: 4) If soil Pl level is greater than the optimum range, then: P20S recommendation gradually declines to O (see equations below). p REMOVAL (MAINTENANCE) Phosphorus removal values, yield units and optimum soil test Bray 1 phosphorus levels for major MFA forage crops~ listed below. Table I. P20S removal and optimum soil test PI ranges for MFA forage crops. P20S Yield ':roq Code Removgl Unit OQt~!llum ~~~l Test P lbs./ lbs. PI/acre Yield Unit Xi X", Corn (silage Sorghum (silage) 6 Alf.,Alf/ Alf.,Alf/ Alfo,Alf/ -est ton/acre ton/acre Use buildup rec. only 0.06 ton/acre CD/acre Use buildup rec. only 45 to to to to to ton/acre CD/acre

3 -seed 107 Use buildup rec. only 108 -stockpile Use buildup rec. only Overseeding Legumes 109 Use buildup rec. only Clover/ Clover/ Clover/ Trefoil/ 110 Use buildup rec. only ton/acre CD/acre 113 Use buildup rec. only 30 to 40 Trefoil/ CD/acre 30 to 40 Lesped./ 115 Use buildup rec. only 30 to 40 Lesped./ ton/acre 30 to 40 ~..esped. / CD/acre 30 to 40 Warm Sea. -est. Per. 118 Use buildup rec. only 30 to 40 Warm Sea. - Per ton/acre 30 to 40 Warm Sea. Per CD/acre 30 to 40 Bluegrass past CD/acre Bermuda ton/acre Bermuda -past CD/acre Wa.cm Sea. - Ann ton/acre Warm Sea. Ann CD/acre

4 P BUILDUP/DRAWDOWN Soils within the optimum 10 unit PI range for each crop (between Xd and Xe) will have a P20S buildup recommendation of 0. Buildup recommendations will be positive below the optimum soil PI range and negative above the optimum soil PI range given for each crop. If Soil Test PI (X.~) < Desired PI (Xd) Then P20S Buildup = «Xd -Xo) * 8) / years buildup If Xo > Xd and < Xd + 11 then P20S buildup = 0 If Xo > X", Then P205 recommendation = P205 maintenance * «(Xe + 15) -Xo)/15) OTHER COMPONENTS 1 If P20S recommendation is between 0 and 20 lbs./acre, then the P20S recommendation given should be defaulted to 20 lbs./acre. 2) If P20S recommendation is less than I, then the P20S recommendation should be 0. 3 P20S recommendations always rounded up to the nearest S lb. P20S increment.

5 EXAMPLE PHOSPHORUS CALCULATIONS USING A 6 YEAR DEFAULT BUILDUP 1 Soil test Pl = 20 lbs/acre, Yield goal = 3 tons fescue/acre optimum PI = 40 lbs./acre P20S recommendation = maintenance + buildup P20S maintenance = 3 tons/acre x 12 Ibs P20S/ton = 36 Ibs. P20S/acre P20S Buildup = (Xd -XO) * 8) /6 = = 40-20) 20 * 8) /6 * 8) /6 160/ Ibs. P205/acre P20S rec. = = 62.7 rounded up to 65 Ibs. P205/acre 2) Soil test PI= 65 lbs./acre, Yield goal = 5 tons alfalfa/acre optimum PI = 45 lbs./acre, Xe = = 55 lbs PI/acre P205 maintenance = 5 tons/acre x 15 Ibs. P205/ton = 75 Ibs. P205/acre P205 recommendation = P205 maintenance * «(Xe + 15) = 75 * «( ) -65)/15) = 75 * (5i 15) = 25 Ibs. P205/acre -Xo)/15 3 Soil test Pi = 45 1bs./acre (within optimum Pi range), Yield goal = 3 tons fescue /acre Maintenance = 3 tons/acre x 12 Ibs. P205/ton = 36 Ibs. P205/acre Buildup = 0 lbs. P205/acre (within 10 unit opt. range) P20S rec = = 36 rounded up to 40 Ibs. P20S/acre

6 1 2 POTASSIUM (K2O) RECOMMENDATIONS FOR MFA FORAGES Extractable K will expressed as lbs./acre. If lab uses ppm, then that number must be multiplied by 2 If soil K level is less than optimum (Xd), then: K20 recommendation = K20 removal + K20 buildup / f 3 If soil K level is within the optimum range, K20 recommendation -~ K20 removal then: 4 If soil K level is greater than the optimum range, then: K20 recommendation gradually declines to O (see equations below). K REMOVAL (MAINTENANCE) Potassium removal values, yield units and optimum soil test potassium levels for major MFA forage crops are listed below. Table I. K20 removal and optimum soil test K'ranges for MFA forage crops. K2O Yield ~Crop Code Removal Unit Optimum Soil Test K lbs./ lbs. K/acre Yield Unit Xd to X~ Corn (silage) Sorghum (silage ton/acre 250 +!j(cec) ton/acre (CEC) Xd Xd Alf., Alf/Gr 101 Buildup rec. only (CEC Xd Alf., Alf/Gr Alf., Alf/Gr -est ton/acre (CEC) CD/acre (CEC 104 Buildup rec. only (CEC) ton/acre (CEC} Cd/acre (CEC) - Se("lSOn seed 107 Buildup rec. only (CEC)

7 108 -stockpile Buildup rec. only (CEC Overseeding Legumes 109 Buildup rec. only (CEC) Clover/ 110 Buildup rec. only (CEC Clover/ ton/acre (CEC) Clover/ CD/acre (CEC) Trefoil/ 113 Buildup rec. only (CEC) Trefoil/ CD/acre (CEC) Lesped./ 115 Buildup rec. only (CEC) Lesped./ ton/acre (CEC) Lesped./ CD/acre (CEC) Warm Sea. Per. -est. 118 Buildup rec. only (CEC) Warm Sea. Per ton/acre (CEC Warm Sea. Per CD/acre (CEC) Bluegrass past Bermuda CD/acre lbo + 5(CEC ton/acre (CEC) Bermuda -past CD/acre (CEC Warm Sea. Ann ton/acre (CEC War, Sea. Ann CD/acre (CEC

8 K BUILDUP/DRAWDOWN Soils within the optimum 50 unit K range for each crop (between X,j and X",) will have a K20 buildup recommendation of 0. Buildup recommendations will be positive below the optimum soil K range and negative above the optimum soil K range given for each crop. ( If Soil Test K (Xo) < Desired K (Xd) then K20 Buildup = «Xd -Xo) * 3) / Years Buildup I f Xo > Xd and < Xd + 51 Then K20 buildup = 0 If Xo > Xe Then K20 recommendation = K20 maintenance * «(Xe + 50) -Xo)/50) OTHER COMPONENTS r 1) If K20 recommendation is between 0 and 20 lbs./acre, then the K20 recommendation given should be defaulted to 20 lbs./acre. 2) If K20 recommendation is less than I, then the K20 recommendation should be 0. 3) K20 recommendations will always be rounded up to the nearest 5 lb. K20 increment.

9 EXAMPLE POTASSIUM CALCULATIONS USING A 6 YEAR DEFAULT BUILDUP 1 Soil test K = 100 lbs/acre, Yield goal = 3 ton fescue/acre CEC = 10 meq/100g. Therefore, optimum K = 230 lbs/acre K20 recommendation. ~ maintenance + buildup K20 maintenance = 3 ton/acre x 40 1bs K20/ton = 120 1bs. K20/acre Buildup = ( Xd -Xo) * 3) / 6 = = ( ) * 3) /6 130 * 3) /6 390/6 = 65 Ibs. K20/acre K20 rec. = = 185 Ibs. K20/acre 2 Soil test K = 400 lbs./acre, Yield goal = 5 ton alfalfa/acre CEC = 12 meq/100g. Therefore, optimum K = 310 lbs./acre X~ = = 360 lbs. K/acre maintenance = 5 ton/acre x 50 Ibs. K20/ton = 250 Ibs. K20/acre K20 recommendation = maint. 250 * 250 * * ( ( (Xe + 50) -Xo)/50) ( ) -400)/50) 10/50) 50 Ibs K20/acre 3) Soil test K = 250 lbs./acre, Yield goal = 3 ton fescue/acre CEC = 12 meq/100g. Therefore optimum K = 240 lbs./acre Optimum K range = 240 to 290 (soil test K of 250 is within) Maintenance = 3 ton/acre x 40 Ibs. K20/ton = 120 Ibs. K20/acre Buildup = 0 lbs. K20/acre (within 50 unit opt. range) K20 rec = = 120 1bs. K20/acre

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