As it is well know qualitative and timely done fertilizing is a pledge of good yield for agrarians. But nowadays manufacturers of agricultural products are in such conditions when every applied kilogram of fertilizer should be economically reasonable and repaid by crop increase as much as possible. For example, if grain crops lack nitrogen crop capacity and grain quality goes down, meantime excessive quantity of the element leads to deterioration of phytosanitary condition, plants lodging and unwarranted expenses. So how should you calculate an optimal quality of nitrogen fertilizers necessary for applying on your field? If you look at it in a right way and can organize everything, then you can manage. But how?

Agrochemical analysis of ground can be carried out and according to its results one can calculate need of nitrogen fertilizers for the whole period of crop growing for planned yield, and only then apply calculated norms of nitrogen fertilizers during the best periods for particular crop.

      But even having done all calculations concerning application of fertilizers planned norms we cannot be sure that our plants are insured against stressful situations connected with nitrogen lack. Lack of moisture or not enough sulfur supply may be the reason of nitrogen shortage in the plant. As content in the ground is not always content in plants. That is why during the process of crop growth it is better to diagnose nitrogen provision according to the plant itself. It can be done in a couple of ways. Let’s say, to make express or laboratory diagnostic of plant parts on nitrogen content and to compare the gained results with optimal level for this crop in the particular growth phase.

      Diagnostic can be done in labs. But will they identify there the level of plant provision with nitrogen in this vegetation phase with particular recommendations? Majority of labs give only bare figures but agrarian most likely should draw conclusions himself. As we see issue of winter crops fertilizing is not so easy as it seems at first sight.

      In order to avoid mistakes and to get necessary result in 2010 the nitrogen sensor GreenSeeker was put into operation in Ukraine.

     GreenSeeker N-sensor is a system for differential application of nitrogen fertilizers and drawing up of biomass maps and application norms basing on crops measuring in real time. Sensors measure plants NDVI (standardized index of plant cover differences). They gather data which may be used for NDVI mapping and norms (where it is possible) for crops analysis and statistical data gathering. This data can be used together with agronomical information to determine need for nitrogen, crop condition, crop capacity potential, crops resistance against falling, vermin and illnesses in quantitative form.

     GreenSeeker N-Sensor can be used for control of crop state change during vegetation period. Spreader or sprayer with electronic computer insures differential application of nitrogen fertilizers in real time (when sprayer / spreader moves over crops). Algorithm and parameters of differential norm on basics of NDVI may be chosen in the field and all norm changes then are made on the turn which excludes long delays between crops evaluation and application.

    Now GreenSeeker sensors work in Vinnytsia and Chernigiv regions. For the short period of work this device has shown itself to enough good advantage during operation in our conditions and with our agricultural crops. But we will tell you about it further.

    Initially farm agronomists had skeptical attitude to the new device and feared for their fields (namely for possible deviation from fertilization norms suggested every year). Tractor-drivers in their turn also looked with suspicion on updating of their “horse” and one more computer in already stuffed case or MTZ with foreign spreaders. Though after second fertilization of winter wheat and after some period of time leveled crops in the field were visible to the naked eye. And plants that had had weak look mainly caught up with the growth of neighbor ones. In conditions of entire application of nitrogen fertilizers leveling in the field was not seen. Such approach leads to falling of yield part and difficulties during combining.

     Except leveling in the field we also have economy of fertilizers: agronomist suggested 150 kg/ha of ammonia nitrate and by using differential application with the help of GreenSeeker at the average 121.3 kg/ha was applied (19.2 % fertilizer economy).

     As a result fertilizers economy per 1 ha is almost 30 kg and per 100 ha it is already 3000 kg, which in money equivalent amounts 6-7 thousand UAH. Positive economic effect of differential fertilization with nitrogen using GreenSeeker N-Sensor for grain crops is in a range 60-80 UAH per ha. By such result investment in GreenSeeker N-Sensor repays itself in 2-3 years if planted area for grain crops is 1000 ha and depending on the frequency of fertilization.

      After wheat fertilization electronic data was received, there one can clearly see intensity of plant coloration in the field (biomass map), and also map of nitrogen application norms. On the gradation of nitrogen application we observe tendency of spreader’s work, which is inversely proportional to biomass map taking into consideration recommendations for this phase of plant growth and for this very type.  

So we see that minimum nitrogen fertilizers (in some places 0 kg) were applied on the third part of the field. I.e. plants on these areas are very well developed and don’t need much nitrogen for normal vegetation. On some areas one can observe considerable lack of nitrogen in the ground that could not be covered by equal standard fertilization. The sensor has coped with the issued task and has given right commands of application norms for the spreader, so it has applied optimal nitrogen quantity on different areas of the field.  

Possibility to change variation (for example, from 0 to 50 kg/ha etc.) let available 100-150 kg/ha of ammonium nitrate divide over the field with more use and output.

      Using the right level of nitrogen for the crop and having got rid of field dissimilarity we can get considerable increase of grain quantity as well as its quality. Now only first step is being made in this direction but what we considered fantasy yesterday is already reality today. The problem which couldn’t be solved in any way today isn’t a problem already. Next stage is exact application of phosphorus-potash fertilizers. Solving of field dissimilarity problem due to main nourishment elements will give an opportunity to stabilize effectiveness of agriculture and to optimize economy of fertilizers use.     

Results of Green Seeker N-Sensor practical application

Basic indexes quality of harvest winter wheat are at differential technologies of growing