New fertilizer: technological innovation still needs to be deepened and product quality needs to be improved.

At present, the new fertilizer is becoming the focus of the chemical fertilizer industry, because it meets the new situation of agricultural development and the needs of industrial upgrading. However, under the huge market pressure, some enterprises dabble in technological innovation and are content to hype new concepts and create new gimmicks. Compared with the agricultural developed countries, the road of fertilizer innovation in China is still very long, and the space is still very huge.

one

The application of slow and controlled release fertilizer is limited by multiple factors.

It's not easy to control.

In the new fertilizer family, slow and controlled release fertilizer is undoubtedly one of the most important varieties. Since 2000, China's slow and controlled release fertilizer industry has entered a stage of rapid development. As of 2011, China has become the largest country in slow and controlled release fertilizer production and consumption, with an output of 700000 tons that year, followed by the United States and Canada, which are 600000 tons and 150000 tons respectively.

As far as farmers are concerned, any new type of fertilizer must eventually increase production, and slow and controlled release fertilizers are faced with such a problem. Some agricultural experts in China have done a control experiment with a total sample size of 93. The results show that nearly half of the samples are of average yield, the proportion of increasing production is less than 40%, and 14% of the samples are reduced. This survey data may be significantly different from our common corporate propaganda in terms of feeling.

Why can't slow and controlled release fertilizers work as soon as they are controlled? The author believes that slow and controlled release fertilizer does not dominate the world, and it is also limited by multiple factors, such as application region, crop, season, application method and so on. The effect of slow and controlled release fertilizer varies greatly in different areas and different crops. the fertilizer efficiency is largely determined by the application technology.

At the same time, there are still many shortcomings to be overcome in the manufacturing of slow and controlled release fertilizer. For example, for organic coated slow and controlled release fertilizers, organic materials as coated fertilizers are expensive and will bring secondary pollution; sulfur coated slow and controlled release fertilizers will aggravate soil acidification and may not be suitable for acid soils and vegetable gardens in the south. Hydrogen sulfide toxicity will also be brought in the paddy field; while the use of inorganic coated slow and controlled release fertilizer, the biggest problem is that the control effect is difficult to be guaranteed. In addition, both sulfur-coated and inorganic coated slow-and controlled-release fertilizers have limitations on nitrogen content, which is not conducive to the preparation of high concentration blended fertilizers.

In the technical innovation of slow and controlled release fertilizers, special attention should be paid to the research and development of natural cheap slow and controlled release materials, such as oxalic acid amide, modified humic acid, polymerized glutamic acid, fermented alginic acid and so on.

two

The effect of stable fertilizer on increasing crop yield

Not necessarily stable.

Stable fertilizer is actually a kind of slow-release fertilizer, but it takes a chemical inhibition approach to slow down the loss of nitrogen volatilization. Stable fertilizers generally use two kinds of inhibitors-urease inhibitor and nitrification inhibitor.

Domestic studies have found that the fertilizer utilization efficiency of adding urease inhibitor is more than 30%, which is about 5.2% higher than that of urea nitrogen without urease inhibitor. After adding nitrification inhibitors, nitrogen fertilizer can be kept in the soil in the form of ammonium nitrogen for a longer time, and ammonium nitrogen can be directly absorbed by crops, so the loss rate is greatly reduced.

However, the effect of stable fertilizer on increasing yield is not necessarily stable. Due to the changeable soil environment, urease inhibitors did not show a stable yield-increasing effect in field experiments. After synthesizing the relevant data, foreign scholars have concluded that in those areas where crop yield potential is large, the level of soil nitrogen is low, and soil and environmental conditions are favorable for ammonia volatilization, the application of fertilizers containing urease inhibitors will have the greatest benefit.

Similarly, nitrification inhibitors have a similar situation. The yield-increasing effect of nitrification inhibitor fertilizers is unstable due to different soil fertility levels, different crop types, various nitrification inhibitors and soil itself.

More importantly, stable fertilizers have potential environmental risks. On January 25, 2013, the world-famous New Zealand milk was exposed to contain the toxic substance dicyandiamide. Later, an investigation found that some pastures were sprayed with chemical fertilizers containing dicyandiamide to cultivate forage grass, resulting in milk contamination. In fact, dicyandiamide is one of the inhibitors in stable fertilizers.

It can be seen that in the development of stable fertilizers, the development of more adaptable varieties and the search for safer inhibitors should become the focus of technical research.