The mechanical deep application of chemical fertilizer technology is a practical technique for applying the deep-applied implements to the soil in a timely and even manner according to the variety, quantity, fertilization site and depth of the agronomic requirements. The mechanical deep application of chemical fertilizer should be combined with soil testing and formula fertilization technology, micro-fertilizer application technology, organic fertilizer application and crop model cultivation technology to exert comprehensive benefits. At present, it is mainly used in land cultivation, sowing and cultivating management of crop cultivation.

I. Technical points for deep application of chemical fertilizers

(1) Deep application of chemical fertilizers in dryland crops

1, the bottom of the deep application

Should be combined with soil tillage operations. At present, there are two methods. One is to first plow and then plow, and the other is to apply fertilizer to the furrow.

(1) The deep application method of first spreading and then ploughing, it is necessary to shorten the time when the fertilizer is exposed to the surface, especially for the fertilizer which is volatile in the air such as ammonium bicarbonate, and to be buried with the fertilizer Into the soil, this kind of fertilization method can be installed with a spreader before the plow, or a special spreader can be used. The fertilizer bandwidth is basically the same as the rear plowing.

The operation requirements of first ploughing and ploughing are as follows: the fertilizer is applied evenly, and the application amount is in line with the agronomic requirements of crop cultivation. After ploughing, the fertilizer is buried in the soil with a depth of more than 6 cm, and there is no visible particles on the surface.

(2) The method of ploughing and fertilizing can basically achieve the simultaneous effect of ploughing and fertilizing, avoiding the volatilization loss caused by the open fertilizer of the fertilizer, generally transforming the existing ploughing plough, increasing the fertilizer discharging device, usually the fertilizer discharging conduit Installed behind the ploughshare, the fertilizer is applied to the surface of the rake or the bottom of the furrow as the ploughshare is turned over (adjusted according to the local agronomic requirements), and then the ploughshare is covered and turned over to achieve the purpose of deep fertilization. Many places are used to calling this method. Fertilize the furrow.

The requirements of the bottoming and ploughing of the bottom fertilizer are as follows: the depth of fertilization is more than 6cm, the width of the fertilizer belt is 3~5cm, the fertilizer is even and continuous, and there is no obvious broken strip. The amount of fertilizer is sufficient to meet the agronomic requirements of crop cultivation.

2, deep application of fertilizer

The fertilizer must be applied deep at the time of sowing, which can be done by installing a fertilizer tank and a fertilizer discharge device on the planter. The requirements for the implements are not only to strictly guarantee the amount of fertilizer, seeding, depth, plant spacing and row spacing according to the agronomic requirements, but also to form a soil thickness of a certain thickness (generally above 3 cm) between the seeds and the fertilizer. To meet the needs of nutrient components in crop seedling growth, and avoid the phenomenon of burning and burning seedlings mixed with fertilizers. The application of this technology requires high soil treatment of the field, and the soil depth should be consistent and no leakage should be done. When the soil is broken, the soil is so real.

According to the position of fertilization and seeds, there are two types of lateral deep application and deep deep application (commonly known as fertilizer and seed layering). The technical requirements are as follows:

(1) Lateral application of fertilizer: fertilizer is applied to the lower side of the seed. The wheat seed fertilizer is generally 2.5~4cm on the side and the bottom of the seed. The depth of the corn seed fertilizer is generally 5.5cm, and the width of the fertilizer belt should be more than 3cm. The fat strip is even and continuous, and there is no obvious broken strip and leakage.

(2) Deep application of seed fertilizer: The seed fertilizer is applied directly under the seed bed. The soil separation layer between the fertilizer layer and the seed is more than 3cm, and the seed and fertilizer are uniform in depth, the fat strip is even and continuous, and the width of the fertilizer belt is slightly larger than Seeding width.

At the same time of sowing, the fertilizer is applied to the soil as a seed fertilizer, and the distance between the seed and the fertilizer should be determined according to the type of fertilizer and the amount of application, so as to prevent the seed and fertilizer from being too close to cause burning seedlings.

3, topdressing

According to the agronomic requirements, the fertilizer application, depth and location use the topdressing machine, and the machine completes the topdressing operation of multi-steps such as ditching, fertilizer removal, soil covering and repression, and it is applied in depth with artificial surface application and hand tools. It can significantly improve the utilization rate and operation efficiency of fertilizers. The top dressing machines should have good inter-row performance and have no obvious adverse effects on the growth of crops (such as wounds, wounds and lodgings). The depth of top dressing (based on the intersection of crop plants and ground) should be 6~10cm. The topdressing position should be between 10~20cm on both sides of the crop line, the width of the fertilizer belt is more than 3cm, no obvious broken strips, and the coverage is strict after fertilization.

(2) Deep application of chemical fertilizers for paddy crops

(1) Deep water application at the bottom of the paddy field

Combined with the operation of the paddy field preparation machinery, the fertilizer box and the fertilizer discharge device are installed on the tillage machine. At the same time as the tillage operation, the chemical fertilizer is applied to the former furrow, and then the soil is buried deep into the soil. After the soil preparation operation, the chemical fertilizer is uniformly mixed into the soil to achieve the purpose of deep fertilization. The depth of fertilization is required to reach 6~10cm, the depth is consistent, the fertilizer is even and continuous, there is no obvious broken strip, and the fertilizer content meets the requirements of local agronomics. In areas where hydroponic operation is carried out, the amount of field water (water depth 1~2cm) should be strictly controlled before tilling and fertilizing, so that it does not affect the tillage operation and ensure the quality of deep fertilization.

(2) paddy field topdressing

It is difficult to use the machine. At present, the human fertilizer is generally used to apply the granular fertilizer to the root of the plant.

Second, fertilizer application equipment specifications

(1) Performance requirements for chemical fertilizers

The deep-appliance machine should meet the fertilization depth (≥6cm) of several suitable crops for agronomic requirements. It has a device that can adjust the amount of fertilizer. The fertilizer device has high reliability, and there should be no broken strips during operation. The width variation is ≤1cm, and the single-season job change or fault repair does not exceed 1 time/set (piece, group).

(2) The application of chemical fertilizers in deep application should meet the following requirements

(1) The rate of broken fertilizer is <3%.

(2) Fertilizer uniformity: 20%~30% of ammonia hydrogencarbonate, and 20%~25% of urea and other granular fertilizers. Among them, the variation coefficient of uniformity of deep fertilizer application is ≤60%; the coefficient of variation of uniform application of fertilizer for deep application is ≤40%; the variation coefficient of uniformity of cultivating deep application of fertilizer is ≤40%.

(3) The coefficient of variation of the uniformity of each row should be ≤13%.

(4) The soil coverage rate of fertilizer should reach 100%, and the fertilizer and topdressing operations should ensure the compaction.

(5) The accuracy of fertilization position is ≥70%.

(6) 3% of cultivating deep-seeking fertilization operations.

(7) The reliability coefficient of use of various machines should be ≥90%.

(III) Operational specifications for chemical fertilizers

1. The operator must undergo special technical training before performing the deep chemical fertilizer application, so as to be familiar with the operation points of the deep application technology of the fertilizer and master the operation and use technology of the machine. Let the operator understand the performance of the deep-appliance machine, and can adjust the machine and remove common faults in the operation of the machine as required. Generally, 2 to 3 operators are suitable for each large and medium-sized machine, and the machine is relatively stable.

2. Before the deep application, check the technical condition of the machine, and check whether the joint parts of the fertilizing machine or the device are tight, whether the lubrication condition is good, and whether the rotating part is flexible.

3. Adjust the amount, depth and width of the fertilizer to make the machine meet the agronomic requirements. When adjusting, the amount of chemical fertilizer in the fertilizer tank should account for more than 1/4 of the volume, and the fertilizing machine or device is placed in a horizontal state, and then the ground wheel is rotated according to the actual working speed, and the number of revolutions is equivalent to the traveling length of 50 m. According to the conversion, the fertilizer is taken and weighed at each fertilizer outlet, and the amount of fertilizer per unit area is calculated according to the following formula.

10qπD·n·a·m(1+δ)

Where Q is the amount of fertilizer applied (kg/hm2);
Q——the average number of total fertilizer discharges (g);
D——ground wheel diameter (m);
N——the number of turns of the ground wheel;
A——average line spacing (m);
M——the number of fertilizer dischargers;
δ - slip coefficient.

After determining the fertilization amount, the machine will enter the ground to carry out the actual operation test. When the machine is stable in the soil, the width and the number of observation points are selected according to the situation. The measurement bandwidth of the fertilizer belt in the section and the shortest distance between the fertilizer and the surface and the seed (plant) are obtained. If the multi-point test meets the requirements, it can be put into normal fertilization operation.

4. To properly apply chemical fertilizers during operations, the following basic principles should be followed:

1 Select suitable fertilizer varieties According to soil conditions and crop characteristics, select fertilizer varieties, determine the reasonable fertilization process (such as the ratio of base fertilizer and top dressing, the number of top dressings and the amount of top dressing), in order to give full play to the fertilizer effect (such as nitrate Nitrogen fertilizer should be avoided on the paddy field to prevent nitrogen loss due to nitrification and denitrification.

2 Fertilizer combined with organic fertilizer application of chemical fertilizer and organic fertilizer, using complementary effects to meet the needs of crops for nutrients in each period. By applying organic fertilizer, the adverse effects of single application of chemical fertilizer on soil physical and chemical properties are avoided, and the soil fertility and fertilization capacity are improved. There are two methods for the application of chemical fertilizers and organic fertilizers. One is organic fertilizer as base fertilizer, chemical fertilizer is used as top dressing or seed fertilizer application; the other method is direct application of organic fertilizer and chemical fertilizer. It should be noted that chemical fertilizers and organic fertilizers can not be mixed arbitrarily, some can improve fertilizer efficiency after mixing, and some will reduce fertilizer efficiency, such as nitrate nitrogen fertilizer (such as ammonium nitrate) and unfertilized compost, manure or fresh straw mixed heap. Hey, under anaerobic conditions, due to denitrification, it is easy to cause nitrate nitrogen to turn off and lose nutrients.

3 According to the fertilization amount and the appropriate proportion of various nutrients, fertilization and fertilization are not only to obtain higher yield, but also to have higher economic benefits. According to soil conditions, crop types, fertilizer varieties and fertilization methods Specific conditions determine the appropriate amount of fertilization and various nutrients. The high yield and stable yield of crops require the coordinated supply of various nutrients such as nitrogen, phosphorus and potassium. The application of a single chemical fertilizer often fails to meet the needs of crop growth and development. According to the current distribution of soil nitrogen, phosphorus and potassium in China, the north should pay attention to the mixed application of nitrogen and phosphorus fertilizers, and the south should do the mixed application of nitrogen, phosphorus and potassium fertilizers.

In addition, according to agronomic requirements and fertilizer characteristics, determine the application season of fertilizer, fertilization sites (such as deep application in the lateral position, deep application in the deep position), fertilization methods (such as concentrated application, topdressing outside the root), etc., in order to improve the utilization rate of fertilizer Create conditions.