Alfalfa. Dr. AJ Foster Southwest Area Agronomist Kansas State University Garden City, KS

Transcription

1 Alfalfa Dr. AJ Foster Southwest Area Agronomist Kansas State University Garden City, KS

2 You can t fi a plant, ou simply give it the right condition to flourish. The key is to know what those condition are.

3 Alfalfa Production Realistic goal. Increase production efficiency Variety Selection High yielding, good disease resistance and insect tolerance Fertility management Manage stand properly Establishing and Maintaining a good stand Pest control management

4 The Plant Factory INPUTS OUTPUTS

5 Plant Requirements Depe ds o the fi al product

6 Alfalfa Nutrient Uptake and Removal Alfalfa has higher demand for nutrients than most crops Nutrient Amount Removed lb/ton P 2 O 5 15 K 2 O 60 Ca 30 Mg 6 S 6 N (through fixation) 60 IPNI

7 Alfalfa Root Development Lateral roots and deep roots Root density Fertilizer application increase root growth IPNI

8 Temperature Effect on Nutrient Uptake Cool soil temperatures will: slow nutrient release from soil organic matter reduce diffusion of nutrients to the roots hinder root absorption and translocation Higher levels of nutrients are needed to support vigorous plant growth in cool soil conditions IPNI

9 Soil ph Cooling system Soil ph like Temperature is a Condition and not the Cause of many soil reaction. Regulates Chemical and biological activities Nutrient cycling Microbial activity

10 Alfalfa Response to Soil ph 3 Yield, tons/a Soil ph Follet and Wilkinson, 1995

11 8 Liming Acid Soil Improves Alfalfa Growth and Nutrient Recovery ph 6.1 Alfalfa yield, ton/a ph 4.7 Yr 3 Yr 2 ph 5.3 Yr 3 Yr 2 Yr 3 Yr 2 0 Yr 1 Yr 1 Yr Lime added, lb/a Walworth and Sumner, 1990 (GA)

12 Liming Acid Soil Improves Alfalfa Growth and Nutrient Recovery Alfalfa shoot composition N K Ca ph 4.7 ph 5.3 ph 6.1 Walworth and Sumner, 1990 (GA)

13 Input = Biological N fixation Symbiotic relationship between bacteria and plant

14 N fixation is not FREE Requires energy Microbes obtain energy from carbohydrates Photosynthetically derive carbohydrates from plant Much easier for the plant to take up available N in the soil.

15 Phosphorus Connected with: 1. Photosynthesis by chlorophyll 2. Biochemical synthesis of organic matter 3. Ample organic matter in the soil 4. Proteinaceous composition 5. Soil ph Orga ic aterials that reach the soil ge erally co tai P ra gi g fro % i g Che Cha g 93

16 Phosphorus The inability of P to move to absorbing roots Lower P concentration Higher P concentration Plant root IPNI

17 P Fertilization Increases Nodulation 300 Number of nodules Soil P, ppm % 90% 100% Soil water holding capacity Azcon et al., 1988

18 Alfalfa Response to Added P Fertilizer (STP=8 ppm, ) Total 3-year yield, ton Cut 3 Cut 2 Cut P application rate, lb P 2 O 5 /A Yield response to added P most evident at first cutting Soil P fertility was maintained by small annual applications or a large one-time application James, 1995; Utah

19 P Improves Alfalfa Growth and Recovery Shoot weight, mg/plant P conc., mmol Days after cutting Alfalfa regrows faster after cutting with adequate P 5 Li et al., 1998 Shoots/plant Days after cutting P conc., mmol Alfalfa develops more shoots after cutting with adequate P

20 Potassium the Work Horse Function in carbohydrate production K is also know as the poor man irrigation Higher the N more K needed to do the job K is important to reduce lodging, but don t forget Cu and Mn

21 K Fertilization Increases Nodule Activity Nodule number Nodule weight, mg K 2 O added, lb/a Grewal and Williams, 2002 (Australia)

22 K Fertilization Improves Hay Quality Leaf Drop (%) Leaf Spot Rating Leaf/Stem Ratio (x100) K 2 O added, lb/a Grewal and Williams, 2002 (Australia)

23 K Helps Reduce Winterkill in Alfalfa Plant counts taken in May as % of those previous September 100 No K 100 lb K 2 O/yr Stand density (%) Year Bailey, 1983 (MB)

24 Luxury Uptake of K for Dairy Feed K in alfalfa varies from <1.5% to >3% Luxury uptake when soil K is very high K levels above 3% unnecessary Liquid manure systems efficiently recycle K High K forage: A concern for dry dairy cows Leads to milk fever, retained placentas after calving For the transition period (2 to 4 weeks before calving) forage with <2% K desired; dietary K should be <1.2% Corn silage, grains, distillers grains are low K feeds Anionic salts (chlorides or sulfates of NH 4+, Mg, or Ca) can help correct the problem IPNI

25 K Competes with Other Cations for Plant Uptake: Mg 0.3 Tissue Mg, % Magnesium Concentrations in Alfalfa K applied, lb K 2 O/A Burmester et al., 1991 (AL)

26 K Competes with Other Cations for Plant Uptake: Ca Tissue Ca, % Calcium Concentrations in Alfalfa K applied, lb K 2 O/A Burmester et al., 1991 (AL)

27 K Fertilization Reduces Uptake of Other Soil Cations: Na 3000 Sodium, ppm Sodium Concentrations in Alfalfa K applied, lb K 2 O/A James, 1988 (UT)

28 Fertilization According to Soil Test Recommendations Yield, tons/a Recommended K rate Yr 3 Yr 2 Yr K applied, lb K 2 O/A Burmester et al., 1991 (AL)

29 Manure Management Manure supplies many nutrients but usually not in the ratio required for alfalfa! Nutritional problems N can stimulate weeds excessive K can cause cation imbalance in dairy feed rations

30 Know Where You Stand Soil Testing Pays If you don t Soil Test, you will be force to guess!!!

31

32 Contact Information Anserd Julius (AJ) Foster, Ph.D. Extension Agronomist Southwest Research- Extension Center Office: Cell: