At Kiwi Fertiliser we are specialists at balancing the soil, having undergone intensive training. If you are contemplating Lucerne as a crop, read on for extensive information.
Lucerne is not a crop that can be rushed into service. The first step is a soil test to establish what is required by way of soil fertility. We recommend PAL in Missouri, so we take samples and complete the paperwork for you.
Lucerne is a very high quality but hungry crop. With a benign climate becoming less reliable, Lucerne offers the opportunity to at least part drought-proof your property and profit. In addition, expensive bought in feed can be reduced or eliminated.
Many crops in NZ are not at all performing to their potential because they are underfed. These crops invariably suffer from weed, pest and disease problems, including premature leaf-drop, and eventually peter out long before they should. Often they are yellow-coloured in spring.
The solution is to balance the soil with quality fertiliser products. In most cases, some capital fertiliser is required, but it can be applied progressively as the budget allows over the first two seasons.
Shortcuts never work. If the crop requires certain fertilisers within a year, they must be applied. The paddocks need to be properly selected and well prepared. That could take a year or more depending on the circumstances. If the paddock is chosen in advance, certain materials such as lime, Dolomite and boron can be applied early, to the existing pasture.
The crop needs to be in the ground by the first week in April, or you should delay until spring. If spring sowing, try to get it in before October 1st, otherwise yield will be decreased for the first year. Spring is the preferred season for planting. Lower temperatures in autumn encourage root growth, but not vegetative growth. That can lead to weeds out-competing the Lucerne.
Up to 20-22 degrees soil temperature, more root growth takes place. Over 22 degrees, more top-growth takes place, so this sets the calendar for establishment. There is risk of dry summers, so it is important to be on time unless irrigation is an option.
The key to soil fertility is calcium and magnesium. If a soil has a deficit of calcium and magnesium, plants will not be able to get their full ration of either nutrient. If sulphur is below optimum, plants will not get the correct amount of calcium and magnesium either.
It is very common for us to see sulphur at the incorrect level. The deficits can be rectified by the application of calculated amounts of lime and/or Dolomite. Lime will release its nutrients over three years; dolomite over 18 months, so benefits will accrue well past application and need to be factored in correctly.
A 20t/ha crop of Lucerne will remove 500kg of nitrogen. 70% of that will come from the air if the Ca:Mg is correct. That’s 350kg; about 100kg will come from the soil leaving 50kg to be added. Do you add N to your Lucerne? Most phosphorus levels we see on flat land are excessive. (E.g. 1100kg/ha when 560 is all that is needed.) For the few soils needing phosphorus, stay with alkaline phosphates.
We find the two most deficient elements are sulphur and potassium. Get sulphur levels to at least 50ppm. Excellent levels are 100-150ppm. The better the humus, the better it will retain anions. That opens the door for compost.At Kiwi Fertiliser, we add 250kg/ha or more of high quality compost when we can; or a lesser amount of humates. Often potassium is half or less of requirement. Where animals graze pastures, adding potassium has its challenges. But if the crops are used for supplement, the opportunity to correct potassium must not be missed. In fact, it is essential.
Correct calcium and magnesium levels in the soil are vital for controlling potassium levels in the herbage. Potassium translates into quality, quantity and disease tolerance. It hastens recovery after harvest, and ensures long-life of a stand. Leaf-drop and spotting are eliminated. It also improves leaf to stem ratio, winter hardiness, and N-fixing.
But there is a catch. The higher the potassium content of Lucerne, the lower the calcium, magnesium and sodium content. The higher the chlorine content, the lower the nitrogen, sulphur, boron and phosphorus content. This means lower protein and lower quality. We prefer to use potassium sulphate, not potassium chloride.
Concerning trace elements, boron is essential and needs to be at least 1.75ppm. Copper at 2-15ppm, preferably 10 or more. Zinc must line up with phosphorus. High phosphorus, high zinc & vice versa. Iron must always read higher than manganese; not the other way around. Selenium confers insect tolerance, and cobalt and molybdenum are essential for nitrogen fixation.
There are several things that caught my eye while scanning through a Beef and Lamb Lucerne blog. Chemicals, insects, weeds, and fertiliser are among them. The Americans use Alfalfa to mop up nutrient excesses. We seem to use Lucerne to create deficiencies. The American excesses are a result of feed lot manure from 50,000 or whatever number of cattle being spread on relatively small areas of land. They then plant Alfalfa and cut that for forage for the cattle for a few years, then perhaps lease the area out to a vegetable grower for a while before the cycle starts again. They are not legally allowed to use the manured areas for at least two years to produce food for human consumption because of Salmonella concerns.
Lucerne is a gross-feeder. It is a very hungry crop. If you want it to out-last and out-compete weeds, then feed it. If you want to produce 20t/haDM and more, then that crop will remove approx. 500kg N, 440 K, 275 Ca, 56 P, 56 Mg, 56 S, and 1.2 Mn, 1 Cu 0.8 B 0.4, Fe 0.4, Zn 0.3, and Mo 0.02. These figures may vary, but what matters is, the crop will take all you throw at it, and in 90% of cases, more. Let’s work through the list. Nitrogen, 70% from the air is 350 kg; then 100 kg from the soil is 450 kg, leaving 50 Kg to be applied from the bag. That 70% from the air is not by necessarily correct either. You’ve got to earn that right. That is achieved by ensuring you have: (1) adequate calcium and magnesium in the correct amounts. This requirement is calculated for each soil. (2) Available phosphate, at least 560kg/ha. (3) Available iron, at least 200ppm, but be aware, iron may be found at depths beyond the soil probe. (4) Cobalt at about 1ppm and (5) Mo at about 1ppm.
Potassium is perhaps the nutrient we have found to be the most deficient; about 50% in most cases. Not only that, but most people use potassium chloride because it is the cheapest form of potassium. Bollocks! Use potassium sulphate instead. For a start, you won’t get those aphids we keep reading about. I've seen them on neighbouring crops too, but they are only a temporary on our crops, at the beginning of when a grower converts to our programme. You won’t have to spray toxic chemicals. You’ll grow a better crop. Besides that, there are many reasons to change and they all point to greater profit in your pocket.
It seems this phenomenon is very common. That may have you thinking it’s normal. It’s not normal at all. If you get aphids, caterpillars or whatever, change your soil fertility advisor. Either he/she is not recommending the right fertilisers, or you are not spending enough on the right products and too much on the wrong products. Insects are not the result of a deficiency of toxic sprays. Insect problems are a result of poor plant nutrition. Poor plant nutrition stems from nutrient imbalances in the soil. Those imbalances transfer to stock as well. Get the soil nutrition right and never spray poisons again. I've mentioned potassium chloride above. Not enough potassium has a similar effect; so do chemical sprays. Protein synthesis needs to take place, not proteolysis which is the opposite and occurs when the plants are not nourished properly.
“It was discovered that the degree of virus disease increased with the dosage of atrazine. A dose of 20 ppm applied to the soil increased symptoms by up to 100%. That was because the toxin altered the biochemical composition of foliar tissues, particularly phosphorus, potassium, calcium, iron, copper, boron, aluminium and zinc. Plus nitrogen levels were elevated in both corn and sorghum. Similarly, simazine increased nitrogen in wheat by 30%, and raised certain amino acids, including asparagine which is preferred by diseases; i.e. leafhoppers proliferated on maize. 2,4-D caused proliferation of aphids, caterpillars and fungi on maize. Other researchers came up with identical conclusions with 2,4-D use on oats and barley.
Two prominent researchers concluded: “Since 1945, numerous reports tell of increased losses through insect and pathogen attack, despite ever greater efforts at pest control. While it is difficult to calculate to what extent these increases are due to the biochemical and ecological impacts of herbicide use, herbicides have been blamed in numerous cases for causing problems of parasitism in treated plants." Nguyen et al. (1972) studied Alfalfa and stressed; "a good balance" of NPK leads to:
Nutrition of Lucerne decreased through one glyphosate spray the previous season. Boron has reduced 18%, calcium 17%, copper 20%, iron 49%, magnesium 26%, manganese 31%, nitrogen 13%, phosphorus 15%, potassium 46%, sulphur 52%, and zinc 18%. These results continue in the stock that eat the affected crop. They do not stop there either and negatively affect the people eating the meat from such animals.
Fenton (1959) found that treating Lucerne with parathion, toxaphene and dementon, increased populations of aphids. The lessons to be taken from the above is to practice balanced nutrition; an activity easier said than done if you don’t know the rules.
If you have weeds, then the conditions suit them. Change the conditions to suit the crop as outlined above. Sure you may have to spray at the beginning, but once your crop is away, and you feed it properly, those weeds will not keep up. In two or three years, (or less) they’ll be gone. If you do spray, add 1 litre/ha of Fulvic acid to the chemical. It is a carbon source and has the ability to reduce chemical damage to the soil and the plant, while enhancing the target kill without any other additives. The chemical rate can also be reduced by 30%. Fulvic is a very cheap product.
Usually, Lucerne stems are hollow. Not only is a hollow-stem crop lighter, but it also lacks quality. The material that packs the stem centres is pectin. Pectin is made up of polysaccharides that contribute to quality and animal nutrition. Most farmers are growing hollow-stemmed Lucerne. Just cut a stem about 150 mm from the crown and check. If the stems are hollow, find out to what extent. It may start 50 mm above the crow, but become solid again 100 mm or 200 mm further up the stem. Our mission is to fill the stems with the nutrition described above.