Report on the Experiment of Reducing Fertilizer Application for Rice

Report on the Experiment of Reducing Fertilizer Application for Rice

Zhang Yi, Yang Dingyong, Xiang Dehua, Liu Chunhua

(The Cultivated Land Quality Protection and Fertilizer Management Station of Yicheng City, Hubei Province, Yicheng 441400, Hubei)

Abstract: Rice is one of the main food crops, and the fertilizer input accounts for more than 50% of the input of agricultural materials. An experiment was carried out to explore the reasonable fertilization formula and appropriate dosage. It was found that formula fertilization, special fertilizer for rice, and the reduction of 10% of the combined application of organic fertilizer and formula fertilizer had a significantly higher yield increase effect compared with the reduction of 20% of the combined application of organic fertilizer and formula fertilizer. The optimized fertilization scheme was selected through the gradient dosage, providing a fertilization reference for the high-yield cultivation of rice.
Keywords: Rice, Fertilizer Reduction, Formula

1.Experiment Setup and Methods

1.1 Overview of the Experiment

The experiment was conducted in the responsibility field of Lü Chuanpeng in Group 5, Qianfeng Village, Leihe Town, Yicheng City, Hubei Province. Wheat and rice are planted in rotation all year round. The yield per unit area of wheat is 430 kg, and the yield per unit area of rice is 630 kg. There were five treatments with three replicates arranged in a randomized block design. The plot area was 20 ㎡ (length 5 m × width 4 m). The width of the furrow between compartments was 50 cm, the width of the ridge was 30 cm, and the height of the ridge was 25 cm. The rice variety was "Yangxianyou 418", which was bred by the Agricultural Science Research Institute of the Lixiahe Region in Jiangsu Province. The transplanting density was 22 cm × 28 cm, equivalent to 11,000 hills per mu. The rice was transplanted on June 1st. On June 8th, Treatments 2, 3, and 4 were top-dressed with green-up fertilizer. The field was drained and sunned on July 20th, and panicle fertilizer was applied on July 25th. The field was reflooded on August 4th. The control of Chilo suppressalis, sheath blight, and rice planthoppers was carried out twice in late July and mid-August. The rice was mature on September 10th, and field investigation, sampling, and actual harvesting were carried out.

1.2 Soil Conditions

The tested soil was paddy soil. The results of the basic soil analysis were as follows: the soil organic matter content was 26.8 g/kg, the available nitrogen was 86 mg/kg, the available phosphorus was 16.5 mg/kg, the available potassium was 218 mg/kg, and the pH value was 6.6.

1.3 Fertilization Design

The tested fertilizers included 6% organic fertilizer (1-1-4:45) provided by Hubei Yishizhuang Agricultural Technology Co., Ltd., 40% special fertilizer for rice (22-6-12). Urea, calcium superphosphate, and potassium chloride were all purchased on the market and mixed according to the designed nutrients [1]. Treatment 1 had no fertilization (control); Treatment 2 was formula fertilization with a mixture of single-element fertilizers (13.0-6.0-6.0) kg/mu; Treatment 3 was 150 kg of organic fertilizer plus a mixture of single-element fertilizers (11.7-5.5-5.4) kg/mu, with a 10% reduction in nutrients; Treatment 4 was 150 kg of organic fertilizer plus a mixture of single-element fertilizers (10.4-4.8-4.8) kg/mu, with a 20% reduction in nutrients; Treatment 5 used 50 kg of 40% (22.0-6.0-12.0) Yishizhuang special fertilizer for rice plus 2 kg of pure nitrogen (a 12% reduction in nutrients per mu compared with formula fertilization, without topdressing). For Treatments 2, 3, and 4, 65% of the nitrogen fertilizer was used as base fertilizer, and 35% was used as topdressing. The phosphate fertilizer and potassium fertilizer were all used as base fertilizer.

2.Harvest Yield and Analysis

2.1 Harvest by plot, sun separately, winnow cleanly, and weigh as shown in Table 1.

2.2 Analysis of Variance of Rice Yields

The analysis of variance of the yields of each plot [2] is shown in Table 2. Through the F-value test, it is indicated that there are extremely significant differences among different treatments, that is, there is an extremely significant yield increase effect.

A new multiple range test was carried out, as shown in Table 3. Refer to the SSR table to calculate the scale values of extremely significant differences between different means.

The comparison of differences was made based on the average yield of each plot, as shown in Table 4. The experimental results prove that: there is no significant difference between the formula fertilizer and the Yishizhuang special fertilizer for rice; there are significant differences between the formula fertilizer, the special fertilizer and the treatments of reducing the combined application of organic fertilizer and formula fertilizer by 10% and 20%; there are extremely significant differences between the formula fertilizer, the special fertilizer, the treatment of reducing by 10% and the treatment of reducing the combined application of organic fertilizer and formula fertilizer by 20%; there are extremely significant differences when compared with the treatment without fertilization.

2.3 Analysis of Agronomic Traits

The assessment of agronomic traits is shown in Table 5. It was observed that the treatments of the special fertilizer and the combined application of organic fertilizer with a 10% reduction in formula fertilizer have more basic seedlings and more tillers. The formula fertilizer and the special fertilizer have more effective panicles and a higher panicle formation rate. The 1000-grain weight is higher in the treatments of the formula fertilizer and the combined application of organic fertilizer with a 20% reduction in formula fertilizer. Through comprehensive analysis, it is believed that the treatments of formula fertilization, the special fertilizer and the treatment of reducing by 10% have a relatively high nitrogen content, which directly affects the differences in agronomic traits.

2.4 Analysis of Economic Benefits

Different fertilization schemes have different outputs and benefits, as shown in Table 6. The net output value of formula fertilization is the highest, and that of the Yishizhuang special fertilizer for rice is the second. The two are close, with only an increase of 42.27 yuan per mu. Compared with the treatment of reducing by 10%, the formula fertilizer increases the net income per mu by 172.91 yuan, and compared with the treatment of reducing by 20%, it increases the net income per mu by 265.30 yuan. Compared with the treatment of reducing by 10%, the Yishizhuang special fertilizer increases the net income per mu by 130.64 yuan, and compared with the treatment of reducing by 20%, it increases the net income per mu by 223.03 yuan. The treatment of reducing by 10% increases the net income per mu by 92.39 yuan compared with the treatment of reducing by 20%.

3、Conclusions and Discussions

3.1 Reasonable Formulation Promotes the Yield Increase of Rice

Formula fertilization determines the formula according to the nutrient requirements of rice [3], meeting the growth needs of rice throughout its entire growth period. The Yishizhuang special fertilizer for rice has a reasonable NPK formula and adds sensitive medium and trace elements. Under the condition of a 12% reduction in nutrients compared with formula fertilization, there is not much difference, indicating that the combination of major, medium and trace elements promotes the yield increase of rice.
3.2 Application of Organic Fertilizer Can Replace Part of Chemical Fertilizers
Organic fertilizers can improve the soil, enhance soil biological activities, decompose and recycle the remaining nutrients in the soil, improve the utilization rate of chemical fertilizers, and replace part of chemical fertilizers to meet the growth needs of crops [4]. The application of organic fertilizers can promote the root development of rice plants and the growth of seedlings, and encourage tillering. In the middle and late stages, the plants grow robustly, with green leaves and yellow grains without premature aging. It is appropriate to replace about 10% of chemical fertilizers with organic fertilizers. If the substitution amount is too large, it will affect the yield and benefits.

3.3 Optimal Selection of Fertilization Formulas

The experimental results show that compared with the reduction of 20% of the combined application of organic fertilizer and formula fertilization, formula fertilization, Yishizhuang special fertilizer for rice, and the reduction of 10% of the combined application of organic fertilizer and formula fertilization have extremely significant effects on increasing yield and income. It is possible to reduce pure nitrogen by 1-1.5 kg per mu. It is recommended to conduct experiments and demonstrations according to local conditions and promote the application, so as to achieve the reduction of chemical fertilizers, the balance of soil nutrients, the improvement of rice quality, and the reduction of costs and increase of income for farmers.
References:

[1] Monographs on Crop Cultivation (Southern Edition) [M]. Beijing: China Agriculture Press, 2011

[2] Gai Junyi. Experimental Statistical Methods [M]. Beijing: China Agriculture Press, 2000

[3] Zhao Yitao. Soil and Fertilizer Science [M]. Beijing: China Chemical Industry Press, 2009

[4] Gao Xiangzhao. Practical Handbook of Fertilizers [M]. Beijing: China Agriculture Press, 2002