Barley fertilizer recommendations

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Nitrogen

Figure 1. The fall soil nitrate test should be used for nitrogen recommendations in the counties that are shaded.

In Minnesota, barley is either grown for malting or as a feed grain. This intended use affects the guidelines for nitrogen (N) use. Barley can replace corn in a livestock ration. It is a good alternative for corn where soils are droughty and corn yields are frequently limited by moisture stress.

Nitrogen fertilizer guidelines can be based on the results of the soil NO₃-N test or the consideration of expected yield, previous crop, and soil organic matter content. We suggest using the soil NO₃-N test in shaded areas of western Minnesota (see Figure 1).

Use these guideline calculations for fertilizer N:

Malting barley

N_Rec = [(1.5) x YG] - STN_{(0-24 in.)} - NPC

Feed grain barley

N_Rec = [(1.7) x YG] - STN_{(0-24 in.)} - NPC

Where:

EY = expected yield (bu./acre)NO_3-N

STN = nitrate-nitrogen (NO_3-N) measured to a depth of 24 in. (lb./acre) NO₃-N

N_pc = amount of N supplied by the previous legume crop (lb./acre). NO₃-N

Table 1 summarizes these N credits.

Nitrogen credits

Table 1. Nitrogen credits for various legume crops that might precede barley in a crop rotation

Previous crop	1st year nitrogen credit
Soybean	20 lb N/acre
Edible beans, field peas	10 lb N/acre
Harvest sweetclover	10 lb N/acre
Harvested alfalfa*	--
4 to 5 plants/ft²	75 lb N/acre
2 to 3 plants/ft²	50 lb N/acre
1 or fewer plants/ft²	0 lb N/acre
Harvested red clover	35 lb N/acre

Use these credits for the "N_pc" factor in situations where the soil nitrate test is used.

* Add 20 lb. N/acre to the credits listed if the 3rd or 4th cutting was not harvested.

Nitrogen guidelines

Use Table 2 if the soil NO₃-N test is not used. We base these suggestions on a realistic expected yield, previous crop and soil organic matter content. When using guidelines in this table, there is no distinction between malting barley and feed barley.

Barley grown in the first and second years after a legume can utilize the N supplied by legume crops in a rotation.

Table 3 lists the nitrogen credits for a legume crop grown two years preceding the barley. Use these credits when the soil NO₃ - N test is not used. Subtract these credits from the N recommendations listed for the crop sequence when barley is grown after crops in group 2.

Crops in group 1

Alsike clover, birdsfoot trefoil, grass/legume hay, grass legume pasture, fallow and red clover.

Crops in group 2

Barley, buckwheat, canola, corn, grass hay, grass pasture, oat, potato, rye, sorghum-sudan, sugar beet, sunflower, sweet corn, triticale and NS wheat.

Table 2. Nitrogen guidelines for barley for situations when the soil nitrate test is not used

Crop grown Last Year	Organic matter Level*	Expected yield: 50 or less bu/acre	Expected yield: 50-59 bu/acre	Expected yield: 60-69 bu/acre	Expected yield: 70-79 bu/acre	Expected yield: 80-89 bu/acre	Expected yield: 90-99 bu/acre	Expected yield: 100+ bu/acre
Alfalfa (4+ plants/ft²)	Low	0 lb N/acre	0 lb N/acre	10 lb N/acre	25 lb N/acre	40 lb N/acre	55 lb N/acre	75 lb N/acre
Alfalfa (4+ plants/ft²)	Medium and high	0 lb N/acre	0 lb N/acre	0 lb N/acre	0 lb N/acre	20 lb N/acre	35 lb N/acre	50 lb N/acre
Alfalfa (2 to 3 plants/ft²)	Low	0 lb N/acre	0 lb N/acre	15 lb N/acre	30 lb N/acre	45 lb N/acre	60 lb N/acre	75 lb N/acre
Alfalfa (2 to 3 plants/ft²)	Medium and high	0 lb N/acre	0 lb N/acre	0 lb N/acre	10 lb N/acre	25 lb N/acre	40 lb N/acre	55 lb N/acre
Soybeans, alfalfa (1 or less plants/ft²)	Low	30 lb N/acre	50 lb N/acre	65 lb N/acre	80 lb N/acre	95 lb N/acre	110 lb N/acre	125 lb N/acre
Soybeans, alfalfa (1 or less plants/ft²)	Medium and high	0 lb N/acre	30 lb N/acre	45 lb N/acre	60 lb N/acre	75 lb N/acre	90 lb N/acre	105 lb N/acre
Edible beans, field peas	Low	40 lb N/acre	60 lb N/acre	75 lb N/acre	90 lb N/acre	105 lb N/acre	120 lb N/acre	135 lb N/acre
Edible beans, field peas	Medium and high	0 lb N/acre	40 lb N/acre	55 lb N/acre	70 lb N/acre	85 lb N/acre	100 lb N/acre	115 lb N/acre
Group 1 crops	Low	0 lb N/acre	20 lb N/acre	35 lb N/acre	50 lb N/acre	65 lb N/acre	80 lb N/acre	95 lb N/acre
Group 1 crops	Medium and high	0 lb N/acre	0 lb N/acre	15 lb N/acre	30 lb N/acre	45 lb N/acre	60 lb N/acre	75 lb N/acre
Group 2 crops	Low	50 lb N/acre	70 lb N/acre	85 lb N/acre	100 lb N/acre	115 lb N/acre	130 lb N/acre	145 lb N/acre
Group 2 crops	Medium and high	30 lb N/acre	50 lb N/acre	65 lb N/acre	80 lb N/acre	95 lb N/acre	110 lb N/acre	125 lb N/acre
Organic soils		0 lb N/acre	0 lb N/acre	0 lb N/acre	0 lb N/acre	30 lb N/acre	40 lb N/acre	50 lb N/acre

* low = less than 3.0%; medium and high = 3.0% or more

Table 3. Nitrogen credits when barley is grown two years after a legume and last year’s crop was not a legume

Previous legume crop	Nitrogen credit for 2nd year after a legume
Alfalfa (4+ plants/ft²) non-harvested sweetclover	35 lb N/acre
Alfalfa (2 plants/ft²)	25 lb N/acre
Alfalfa clover, birdsfoot trefoil, and red clover	20 lb N/acre

Phosphate and potash

Tables 4 and 5 list guidelines for phosphate and potash fertilizer use, respectively. In general, you can use lower rates of phosphate and potash if placed in a band near the seed. Compared to a broadcast application, you can reduce rates by 1/2 if using a banded application.

Phosphate guidelines

Table 4. Phosphate fertilizer guidelines for barley production

Expected yield	Drill/broadcast	P soil test: 0-5 parts per million (ppm) Bray and 0-3 ppm Olsen	P soil test: 6-10 ppm Bray and 4-7 ppm Olsen	P soil test: 11-15 ppm Bray and 8-11 ppm Olsen	P soil test: 11-15 ppm Bray and 8-11 ppm Olsen	P soil test: 21+ ppm Bray and 16+ ppm Olsen
Less than 50 bu/acre	Drill	20 lb/acre	15 lb/acre	10 lb/acre	10-15 lb/acre	0 lb/acre
Less than 50 50 bu/acre	Broadcast	35 lb/acre	25 lb/acre	15 lb/acre	0 lb/acre	0 lb/acre
50-59 50 bu/acre	Drill	20 lb/acre	15 lb/acre	10 lb/acre	10-15 lb/acre	0 lb/acre
50-59 50 bu/acre	Broadcast	40 lb/acre	25 lb/acre	15 lb/acre	0 lb/acre	0 lb/acre
60-69 50 bu/acre	Drill	25 lb/acre	15 lb/acre	15 lb/acre	10-15 lb/acre	0 lb/acre
60-69 50 bu/acre	Broadcast	45 lb/acre	30 lb/acre	20 lb/acre	0 lb/acre	0 lb/acre
70-79 50 bu/acre	Drill	25 lb/acre	20 lb/acre	15 lb/acre	10-15 lb/acre	0 lb/acre
70-79 50 bu/acre	Broadcast	50 lb/acre	35 lb/acre	20 lb/acre	0 lb/acre	0 lb/acre
80-89 50 bu/acre	Drill	30 lb/acre	20 lb/acre	15 lb/acre	10-15 lb/acre	0 lb/acre
80-89 50 bu/acre	Broadcast	60 lb/acre	40 lb/acre	25 lb/acre	0 lb/acre	0 lb/acre
90-99 50 bu/acre	Drill	35 lb/acre	25 lb/acre	15 lb/acre	10-15 lb/acre	0 lb/acre
90-99 50 bu/acre	Broadcast	65 lb/acre	45 lb/acre	25 lb/acre	0 lb/acre	0 lb/acre
100+ 50 bu/acre	Drill	35 lb/acre	25 lb/acre	20 lb/acre	10-15 lb/acre	0 lb/acre
100+ 50 bu/acre	Broadcast	70 lb/acre	50 lb/acre	0 lb/acre	0 lb/acre	0 lb/acre

Use one of the following equations if a phosphate guideline for a specific expected yield and a specific P soil test is desired.

P₂O_{5 rec} = [0.785 - (0.039) (Bray P, ppm)] (Expected Yield)
P₂O_{5 rec} = [0.785 - (0.050) (Olsen P, ppm)] (Expected Yield)

Potash guidelines

Table 5. Potash fertilizer guidelines for barley production

Expected yield	Drill/broadcast	K soil test: 0-40 ppm	K soil test: 41-80 ppm	K soil test: 81-120 ppm	K soil test: 121-160 ppm	K soil test: 161+ ppm
Less than 50 bu/acre	Drill	25 lb/acre	20 lb/acre	15 lb/acre	10-15 lb/acre	0 lb/acre
Less than 50 bu/acre	Broadcast	50 lb/acre	40 lb/acre	20 lb/acre	0 lb/acre	0 lb/acre
50-59 bu/acre	Drill	30 lb/acre	25 lb/acre	15 lb/acre	10-15 lb/acre	0 lb/acre
50-59 bu/acre	Broadcast	60 lb/acre	45 lb/acre	25 lb/acre	0 lb/acre	0 lb/acre
60-69 bu/acre	Drill	35 lb/acre	25 lb/acre	20 lb/acre	10-15 lb/acre	0 lb/acre
60-69 bu/acre	Broadcast	70 lb/acre	50 lb/acre	30 lb/acre	0 lb/acre	0 lb/acre
70-79 bu/acre	Drill	40 lb/acre	30 lb/acre	25 lb/acre	10-15 lb/acre	0 lb/acre
70-79 bu/acre	Broadcast	85 lb/acre	60 lb/acre	35 lb/acre	0 lb/acre	0 lb/acre
80-89 bu/acre	Drill	50 lb/acre	35 lb/acre	25 lb/acre	10-15 lb/acre	0 lb/acre
80-89 bu/acre	Broadcast	95 lb/acre	65 lb/acre	40 lb/acre	0 lb/acre	0 lb/acre
90-99 bu/acre	Drill	55 lb/acre	40 lb/acre	30 lb/acre	10-15 lb/acre	0 lb/acre
90-99 bu/acre	Broadcast	105 lb/acre	75 lb/acre	45 lb/acre	0 lb/acre	0 lb/acre
100+ bu/acre	Drill	55 lb/acre	40 lb/acre	35 lb/acre	10-15 lb/acre	0 lb/acre
100+ bu/acre	Broadcast	110 lb/acre	80 lb/acre	50 lb/acre	0 lb/acre	0 lb/acre

Use the following equation for a potash guideline for a specific expected yield.

K₂O rec = [1.286 - (0.0085) (K soil test)] (expected yield).

Other nutrients

The use of sulfur (S) and copper (Cu) may be important for optimum barley production in limited situations. If barley is grown on sandy soils, either broadcast 25 lb. S/acre or use 10-12 lb. S/ acre with the drill at planting. You will not need sulfur for barley grown on fine-textured soils.

Table 6 summarizes the Cu suggestions. You will not need copper in a fertilizer program when barley is grown on mineral soils. In Minnesota, barley has not responded to the use of zinc (Zn), iron (Fe), manganese (Mn) and boron (B) in a fertilizer program.

Copper guidelines

Table 6. Copper suggestions for barley grown on organic (peat) soils

Copper soil test	Broadcast	Foliar spray
0-2.5 (low) ppm	6-12 lb/acre	0.3 lb/acre
2.6-5.0 (marginal)* ppm	6 lb/acre	0.3 lb/acre
5.1+ (adequate) ppm	0 lb/acre	0 lb/acre

*Suggestions for marginal soil tests are based on limited trial data.

Daniel E. Kaiser, Extension nutrient management specialist

Reviewed in 2018