Tips for plant nutrition: soil analyses are essential
Efficiency will become the key term in plant nutrition over the next few years. "Whether the driving force will be the upcoming amendment to fertiliser regulations, the need for further optimisation of costs, or the desire to achieve technical progress remains to be seen", said Arne Klages from the Crop Production consultation team at AGRAVIS Raiffeisen AG.
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"We would like to show what options are available and what methods we recommend for improving efficiency based on a plan for fertilising cereals in spring 2016." Before focusing attention on new developments in the field of plant nutrition, soil samples must take place and they should be no more than four years old. The greatest potential for creating a solid yield structure remains, as ever, in ensuring that the pH value is properly set.
"Lime isn't everything, but everything is nothing without lime!"
In line with the motto: "Lime isn't everything, but everything is nothing without lime!" "We advise taking a closer look at soil analyses", said Klages. He recommends that areas with a pH value in the B category undergo stubble liming in summer 2016, whilst areas in the A category should already have undergone top liming at the end of winter.
The macronutrients phosphorus, potash, and magnesium can also be checked at the same time. These should also be within the C area. In addition, the ratio of potash to magnesium should be 2 or 3:1. "Noticeable areas of weakness regarding phosphorus can only be rectified after the harvest in cereals and rape." The expert advises that potash and magnesium should be given to balance out what was lost, using Kornkali and kieserite if necessary at the beginning of the vegetation cycle.
Carrying out liming and basic fertilising depending on specific sub-areas via netfarming.de
A top dressing of phosphorus rarely yields success as the nutrient barely moves in soil and therefore hardly ever reaches the roots of the established culture. In emergency situations, the only possible remedy is to add leaf fertilisers. The new AGRAVIS platform netfarming.de provides the option of carrying out liming and basic fertilising depending on specific sub-areas: "The more irregular the strokes are, the more beneficial views of satellite images of the sub-areas will be. Targeted soil analyses in areas with the same yield potential result in highly efficient application maps for limes and basic fertilisers."
After considering the fundamentals, attention should be given to cereal nutrition. The central element in plant nutrition during spring is nitrogen. "However, it must be pointed out that every useful kilogram of nitrogen can only produce maximum output when both the pH value is in order and suitable basic nutrition is in place", stated Arne Klages. "Nutrients should never be considered on their own; they always have to be considered as part of a whole."
Assessing various parameters
The following parameters should be assessed during a field survey when planning the initial dosage: tillering, soil temperature, ground conditions (for driving), beginning of vegetation cycle, and root regeneration. Depending on results, very well developed stock that can be driven on early on is best served with nitrate-free Piamon. Ammonium sulphate nitrate is appropriate in most cases. Crops that still require much support can be assisted with high levels of nitrate using YaraBela Sulfan or calcium ammonium nitrate plus kieserite. ALZON 25/6 liquid fertiliser can be used as a universal solution. With nitrates, sulphur compounds, and a nitrification inhibitor it is possible to react flexibly to the relevant situation depending on the quantity used. "Particularly on lighter soils, we have managed to achieve high N concentrations with one-off additions of 150 kilograms of nitrogen using ALZON 25/6 in rye and wheat. In this context, the most important issue is that the supply of sulphur in the form of sulphates is already ensured at the start of the vegetation cycle", stated Klages.
Manure or digestate for providing cereals with nutrients
Manure or digestate can be used to provide cereals with nutrients in many areas. The effects of the nutrients nitrogen and sulphur are largely apparent upon stem elongation. However, application occurs as soon as the ground can be driven on, so that losses are as low as possible at cool temperatures and with a cloudy sky. The impending "nitrogen bomb" can be defused in areas with regular organic fertilising by adding liquid nitrification inhibitors such as, for example, ENTEC. Alternatively, a fertilisation strategy with manure or digestate can be started with a mineral supplement with 5.0 quintals of ENTEC 26 per hectare.
Important plant analysis
Just before stem elongation (EC30), a crop analysis on individual operational areas may help in monitoring the entire nutrition supply. Even if all nutrients are available in the soil, there are numerous factors – especially a dry spring – that could result in nutrients not getting into the plants. At the same time, hidden deficiencies can occur that may not be visible, but lead to falling yields. Therefore, if the objective is to achieve efficiency, high yields, and strong balance sheets, a nutrition check via crop analysis may be helpful: "Within cereals there are often deficiencies in copper, manganese, and zinc. Several cases over the last few years have also shown that the element boron is frequently lacking too."
Leaf fertiliser in line with the analysis results
Leaf fertilisation in line with the analysis results for the initial fungicide measure continues to ensure adequate nutrition. If there is a deficiency in the stated key nutrients, the use of PHYTAVIS Getreide Plus may help. Titanium is a nutrient that was not previously considered important in plant nutrition. "For two years we have carried out our own tests on the product Tytanit, with 8.5 grams of titanium per litre. Greater yields were obtained in every test compared to the control samples. A scientific test with winter barley in 2015 delivered a statistically proven increase in yield", reported Klages.
Notes regarding fertilisation strategy
If a multi-stage fertilisation strategy is planned, all typical N single-nutrient fertilisers such as calcium ammonium nitrate, urea, or AHL can be used for stem elongation and for the flag leaf stage. The properties of the fertiliser types should be borne in mind for best use of the nitrogen that has been applied. Urea runs a risk of loss if the granules fall onto dry ground. If the pH value is around 7 and temperatures are considerably above 20 degrees, another type of fertiliser should be chosen instead. Subsequent precipitation, pronounced thaws, dense crop populations, and temperatures below 20 degrees allow for the greatest yields when using urea. Calcium ammonium nitrate is classified as being less dependent on air and ground moisture. However, even calcium ammonium nitrate is not one hundred percent effective.
Isaria sensor determines dosage
Liquid fertilisers must always be applied in coarse droplets; weather conditions as described in the case of urea are beneficial. From the second dose onwards the Isaria sensor can determine the nitrogen dosage for all yield potentials in specific sub-areas. "This means that areas with little potential are given less nitrogen. Sub-areas that can produce high yields are fertilised. Our trials showed that the sensor always found the appropriate yield level and created a good N balance", reported the cultivation expert. If wheat should be grown for baking, then the protein content can be guaranteed with a combined nitrogen-sulphur solution after flowering.
In summary, it can be said that, in principle, the pH value and the basic nutrition can be checked with current soil samples. The selection of nitrogen fertiliser must be adapted to the state of development at the end of February. Plant analyses and tailored leaf fertilisers ensure nutrition during vegetation. The more irregular the areas are, the more suitable it is to consider carrying out cultivation that is specific to sub-areas. Liming and basic fertilising are a simple start and also have the effect of increasing nitrogen and phosphorus efficiency, thus improving the nutrient balance in the soil.
Further information on this topic can be obtained from the Crop Production consultation team at AGRAVIS Raiffeisen AG or directly from Arne Klages, Tel.: +49 (0) 152 01810283, firstname.lastname@example.org.