Alfalfa Planting and Production Management Dr. Bruce Anderson University of Nebraska-Lincoln

Strengths of Alfalfa High yield potential Excellent feed value Long-lived Produces nitrogen (N) Flexible use

Planting New Fields of Alfalfa

Good Sites Fertile Well drained Deep Good moisture

Avoid Poor drainage High water table Saline or salty Shallow

6.

x Lime for Alfalfa Raise pH for improved nodulation Reduce toxic Al and Mn Supply Ca and Mg Improve soil mineralization and increase P, K, and S availability

Soil pH & Nutrient Availability

Nutrients removed by alfalfa MineralLbs per ton N P K Ca S

x Phosphorus recommendations Bray 1Interpretation Dryland Irrigated (ppm) lb/A Very low (VL) Low (L) Medium (M)2030 >25 High (H) 0 0 (P 2 O 5 )

P 2 O 5 (lb/A) 600

x Potassium recommendations Soil KInterpretation K 2 O (ppm) lb/A Very low (VL) Low (L) Medium (M) 40 >126 High (H) 0 (K 2 O)

Sulfur for Irrigated Alfalfa Soil ( ppm ) lb/A to to > OM 1% Irrigation water Sulfate-S ( ppm ) Sulfate-S

Micronutrients BoronIronMagnesiumMolybdenumCopper

x Boron recommendations Soil BInterpretation Boron (ppm) - - lb/A to 0.25 Low (L) to 0.5 Medium (M) 1 >0.5 High (H) 0

THE SEEDBED

SEEDBED CHARACTERISTICS FIRM

Lose more plants in the first 24 hours than in the next 24 months

Effect of planting depth on alfalfa stand establishment Soil type Depth of planting (in) % Establishment Sand Clay

DATE OF SEEDING April April August August

Variety Selection

Selection Criteria Yield Disease resistance Fall dormancy Winter hardiness Forage quality

INNOCULATION Use Proper Innoculant  Use Proper Innoculant  Store in Cool, Dry Location  Mix with Seed and Plant Soon  Nitrogen Fixation

Weeds

MOWING Effective – Broadleaf annuals and some perennials sunflowers, velvetleaf, ironweed Ineffective – Grasses, winter annuals, other perennials foxtail, cheatgrass, sandbur, curly dock, mustards, thistles

Cover Crops

Alfalfa yields using herbicides or oats to control weeds TreatmentSeeding Year 1 st Cut Next Year tons/acre Check Check Poast Poast Buctril Buctril Poast + Buctril Poast + Buctril Poast + Oats Poast + Oats Oats as hay Oats as hay Oats as grain Oats as grain

Alfalfa yields using herbicides or oats to control weeds TreatmentSeeding Year 1 st Cut Next Year tons/acre Check Check Poast Poast Buctril Buctril Poast + Buctril Poast + Buctril Poast + Oats Poast + Oats Oats as hay Oats as hay Oats as grain Oats as grain

Seedling Options Eptam Balan Trust

Seedling Options Eptam Balan Trust Poast Select Pursuit Raptor Butyrac Buctril Roundup

What about ESTABLISHED STANDS? 1 st -2 nd year may have winter annuals or summer grasses 3 rd -4 th production year begin to develop weeds as stands thin   perennial weeds and/or winter annual weeds fill in (opportunistic)   Need to determine if enough alfalfa is present to justify herbicide treatment

Treat or rotate crop? Treat if weedy and have: > 4 to 5 plants/sq ft > 55 stems/sq ft > 2 to 3 plants/sq ft > 35 stems/sq ft If below, consider crop rotation

Weed management in established alfalfa Control weeds in established stands if: Fields have adequate alfalfa density Weeds have low forage quality or impact animal health/performance Herbicides can improve forage quality, but rarely improve yield

Herbicides available for ESTABLISHED STANDS Many herbicides available, but   Few control perennial weeds   Winter annuals need to be applied when small or before emergence (fall to early spring)

Bruce Anderson Extension Forage Specialist Dept. of Agronomy & Horticulture University of Nebraska Lincoln, NE /