NO134626B - - Google Patents

Description

Use of crotylidene diurea as a slow-acting nitrogen fertilizer.

When using commercial fertilisers, efforts are made to adapt the supply of nutrients both in terms of quantity and also with regard to time to the needs of the plants. While, as is known, a stock fertilization is possible and also common with the nutrient phosphorus, most experiences speak against a stock fertilization with mineral nitrogen.

High nitrogen additions can be made in areas with heavy rainfall, e.g. in the tropics and on artificially irrigated surfaces, lead to leaching losses. Likewise, in certain cases, the further increase in yields can be limited as a result of too high a concentration of easily soluble nitrogen salts in the soil.

For a long time, condensation products of urea with formaldehyde, so-called "ureaform" preparations, have been used as slow-acting nitrogen fertilisers. However, the effect of these is unsatisfactory in most cases. It turned out that a certain proportion of the nitrogen present in the form of urea-formaldehyde condensates is already utilized within a very short time, while a large part of the plant cannot be made useful at all. The desired slow and persistent effect occurs with these products only to a small extent.

It now turned out that crotylidene diurea is a slow and persistently acting nitrogen fertilizer. Besides

the steady delivery of the nitrogen has this

compound equal to mineral nitrogen fertilizers also has the advantage that it is only difficult to wash out and also enables a very high dosage without risk to the plants to which the fertilizer is to be added.

The slow action of crotylidene in the urea is also not affected in mixtures with easily soluble, i.e. fast-acting, nitrogen fertilisers, or other nutrients or fertilisers. In the case of granulation or granulation, its effect can also be slowed down further. On the other hand, by mixing different amounts of fast-acting nitrogen compounds, an individual adaptation to the plants' different nitrogen needs in the juvenile stage can be achieved.

The crotylidene in urea can be produced by reacting crotonaldehyde with urea in acidic aqueous solution.

It contains 32-34% nitrogen, depending on the purity of the product. The amounts to be used for fertilizing vary from case to case, as the amount depends on many factors, such as the type of cultivated plants, the condition of the soil, the climate and the season. In the case of a one-off application, for example, the following amounts are taken into consideration as fertilizer additions for the various cultivated plants (expressed in kg of pure nitrogen per hectare, i.e. 1 kg of pure nitrogen corresponds to approx. 3 kg of crotylidene diurea),

The testing of crotylindiurea for its action can easily be carried out in vessel experiments (Mitscherlich vessels). As an experimental plant, pasture grass (lolium perenne) is particularly well suited, as this plant, due to its regeneration capacity, allows several crops (sheds) without having to make a change to the soil structure. In this way, the absorption of the nitrogen and, above all, its persistent effect, can be accurately followed over a longer period of time. Likewise, the controlled water supply allows a comparative test of different nitrogen compounds with regard to their leaching from the soil.

To improve the fertilizing effect, crotylidene diurea can be mixed with other mineral or organic fertilisers, for example fast or slow-acting nitrogen, potassium or phosphorus fertilizers or mixtures thereof or humus-based fertilisers, and then used in this form as a component of .a fertilizer mixture.

To facilitate spreading and to avoid dust formation, the crotylidene diurea can also be used in a mixture with inert materials. Suitable inert materials are, for example, peat, clay and wood waste products (lignins).

The following examples prove the slow fertilizing action of crotylidene in the urea.

Example 1:

In Mitscherlich vessels with a clayey sand bottom, a vegetation trial is carried out with pasture grass as the experimental plant. In addition to a basic fertiliser, which contains phosphorus and potassium compounds, 1.5 g N per vessels in the form of the nitrogen compounds to be examined. The water supply is measured at 60% of the earth's maximum water capacity. No seepage water therefore occurs.

A total of four sheds were made with pasture grass during the trial period lasting from May to November. The yields and nitrogen removal figures are listed in the following table 1. From this it can be deduced that the nitrogen fertilization effect of the crotylidene diurea is significantly slower and more persistent than for the comparison substances.

The yield figures are given in grams of dry substance per vessels and the figures for N removal in mg nitrogen per dude.

, ■ Example 2:

In the manner described in example 1

a vegetation trial was carried out with pasture grass, during which a large quantity of water is added once 7 days before the first shed. The addition of water is measured — after prior water saturation of the soil — to

500 ml per dude. The following amounts of N can be detected in the seepage water:

The figures show that among the different nitrogen compounds, crotylidene di-

urea and urea form the far smallest leaching losses. In the case of the crotylidene diurea, in accordance with this, crop formation (see table 2) also shows a very strong superiority over the compounds with high N leaching. However, this is not the case for urea form, as here the low leaching is compensated by the relatively poor nitrogen utilization. The yield differences between ammonium nitrate, urea form and crotylidene diurea are after the 4th shed at 22.8 : 23.0 : 36.1 g dry substance per dude. In the N recording, the following differences between these three compounds were obtained after the 4th wash:

in

The figures for yield or yield and N removal are given in the same units as in table 1.

Example 3:

To test the question of what damage occurs to cultivated plants when these nitrogen fertilizers are added in larger quantities than usual, an experiment was carried out in Mitscherlichkar with maize. The nitrogen is supplied in the form of ammonium nitrate trat and crotylidene diurea in increasing additions up to 15 g N/bar. During the development of the maize plants, it is observed that with 5 g of N as ammonium nitrate, there is a strong inhibition in juvenile development, while with fertilization with crotylidene diurea even with 15 g of N, no growth depression can be recognized. In the case of the plants that were fertilized with ammonium nitrate, the maize plants that were fertilized with 7.5 and 15 g N wilt, while the plants that were fertilized with crotylidene diurea show very good development. The results of the experiment can be derived from the following table 3.

Claims (1)

Use of crotylidene diurea as a slow and persistently acting nitrogen fertilizer, possibly in combination ding with other fertilizers or inert materials.