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Water

 
 

Irrigation Concerns

By scheduling the water this year, the Irrigation district was able to bank about 94,000 acre-feet of water at El Vado Reservoir in northern New Mexico. That will help supplement next season's supplies.

The problem is the district is concerned its ability to store water in the future could be compromised by how the federal government manages the Rio Grande. The district is weighing in on a lawsuit New Mexico Attorney General Gary King filed earlier this year against the Bureau of Reclamation. 

   

 

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RecentNews

 
 

Casa Colorada

This year a portion of the Casa Colorada ranch was converted to crop production rather than pasture grazing.  Several years were spent removing invasive plant material and leveling the newly created farm.  The farm was planted in Buckwheat as a test crop.  The water table began to rise as the area was cleared of Salt Cedar and Russian Olive.  Buckwheat was recommended as a salt tolerant crop as well as tolerant to the high water table.  

   

 

Our recommendations

 
 

 

Fertilizing Alfalfa

Please read and believe! If you fertilize your Alfalfa without soil testing, please send a check to the American Red Cross instead of purchasing fertilizer.  It will be a much more effective use of your hard earned cash. 


Nitrogen (N) – Some nitrogen (20-30 pounds per acre) is required for establishment of seedling alfalfa.  Once alfalfa seedlings form nodules on their roots, they can fix their own nitrogen from the atmosphere, so no more nitrogen needs to be applied during the life of the stand. Nitrogen fixation is the result of a symbiotic activity of alfalfa and Rhizobium bacteria. For the symbiosis to occur, it is important that properly inoculated seed be used and that the nitrogen-fixing bacteria become active. Response to nitrogen fertilizer after alfalfa is established is a sign that nitrogen-fixing bacteria are absent. A soil test can determine if acidity is the problem, but neither acidity nor inoculation failure can be corrected after the alfalfa is planted.

Phosphorus (P) and Potassium (K)- Harvesting five tons per acre of alfalfa removes more then 50 pounds per acre of P2O5 and 250 pounds per acre of K2O each year. Soils usually can supply some of these nutrients, but phosphorus or potassium fertilizer (or both) often needs to be applied before and during the life of the stand. The fertility levels of P and K  in sandy soil change more rapidly under alfalfa production than with other crops. The best way to determine how much phosphorus (P2O5) and potassium (K2O) to apply is to test the soil.   Because these nutrients (P and K) are considered immobile in the soil, that is, they react with the soil and do not migrate with the soil's moisture content, the most efficient way to get them into the rooting zone is to incorporate them before planting. Applying additional phosphorus and potassium fertilizers to the surface of existing stands is somewhat less efficient, but it is necessary in most fields for profitable alfalfa production.

Phosphorus (P) deficiencies are best corrected by applying and incorporating a three year supply of fertilizer in the summer before fall planting. Soil fertility levels should then be monitored through soil testing, and any addition P should be added following the second or third year of production from November to January, before early spring growth. Best response to surface-applied P is usually obtained in the first cutting. Good surface moisture in the spring results in P uptake by surface roots. Starting the follow-up applications of P in the second year also allows time for some movement of P through soil disturbances caused by insects, cattle, machinery, freezing, etc.

Potassium (K) deficiencies are best corrected by applying only enough for one year because alfalfa will take up more than needed when large amounts are available (luxury consumption). After alfalfa is established, soil should be tested annually after the second year, and K should be applied as needed from November to January, before early spring growth. 


Table 1. Nutrient removal per ton of dry matter alfalfa
Nutrient
Amount Removed (lbs/ac)
Phosphorus (P)
4 - 6
Phosphate (P2O5)
10 - 15
Potassium (K)
40 - 55
Potash (K2O)
50 - 65
Calcium (Ca)
30
Magnesium (Mg)
5 - 7
Sulphur (S)
5 - 7
Boron (B)
0.08
Copper (Cu)
0.01
Iron (Fe)
0.3
Manganese (Mn)
0.1
Molybdenum (Mo)
0.002
Zinc (Zn)
0.05



Table 2. Annual phosphate fertilizer recommendations for irrigated alfalfa.
Soil Test Phosphorus (P)
(0-15 cm depth)
(lb/ac)
Phosphate (P2O5)
Recommendation
(lb/ac)
0 - 10 60
10 - 20 50
20 - 30 45
30 - 40 40
40 - 50 35
50 - 60 30
60 - 70 20
70 - 80 10
>80 0


Table 3. Potash fertilizer recommendations for irrigated alfalfa.
Soil Test Potassium (K)
(0-15 cm depth)
(lb/ac) ppm
Potash (K2O)
Recommendation
(lb/ac)
0 - 50 240 - 260
50 - 100 165 - 180
100 - 150 115 - 125
150 - 175 75
175 - 200 50
200 - 225 25
225 0
Note: Based on the ammonium acetate soil K test method.

Manure and Compost

Manure and compost supply relatively large amounts of phosphorus and potassium. When manure is used as a fertilizer on established alfalfa fields, it can burn leaves, which in turn reduces the yield and quality of alfalfa. Manure application equipment may reduce yields by compacting soil and damaging alfalfa crowns. Generally, it is best to apply manure before establishing alfalfa or during the cereal part of an alfalfa - cereal crop rotation.

Nitrogen in manure may stimulate grass and even weed growth in alfalfa stands; therefore, manure is better used on non-legume crops. If no other land is available, spread the manure on the oldest alfalfa stand or the one with the most grass in it.

Solid manure should be well broken up and applied at a rate no higher than 10 tons/acre. Apply it immediately after a cut, so the manure contacts the soil rather than the crop. To reduce soil compaction, the manure should be applied on relatively firm, dry soil. Irrigation after a manure application will minimize crop damage and reduce nitrogen loss.

Plant Tissue Analysis

Plant tissue analysis will provide additional information on soil fertility and the nutritional health of the crop. At the bud-stage, healthy alfalfa plants contain a minimum of 3.0 per cent nitrogen, 0.2 per cent phosphorus, 1.7 per cent potassium and 0.2 per cent sulphur. Table 4 shows the levels of each nutrient in the top 15 cm of plant tissue at 5 per cent bloom.

Table 4. Levels of nutrients in the top 15 cm of alfalfa tissue at 5 per cent bloom.
Nutrient
Low
Sufficient
Per cent (%)
High
Nitrogen
<3.0
3.0 - 5.0
>5.0
Phosphorus
<0.20
0.20 - 0.70
>0.70
Potassium
<1.70
1.70 - 3.80
>3.80
Calcium
<0.25
0.25 - 3.0
>3.0
Magnesium
<0.20
0.20 - 1.0
>1.0
Sulphur
<0.20
0.20 - 0.50
>0.50
Parts per million (ppm)
Boron
<20
20 - 80
>80
Copper
<5
5 - 30
>30
Iron
<20
20 - 250
>250
Manganese
<20
20 - 200
>200
Molybdenum
<0.5
0.5 - 5.0
>5.0
Zinc
<20
20 - 70
>70

Tissue analysis can help in determining when nutrient deficiencies are present before visual symptoms appear. Coupled with soil tests, tissue analysis allows producers to establish a more comprehensive fertilizer management program for alfalfa.