Analysis of the Impact of Agricultural Mechanization on the Economic Efficiency of Maize Production

Abstract

Against the background of comprehensively promoting the rural revitalization strategy, the replacement of agricultural labor by agricultural machinery in the hilly area of southwest China has become an indispensable input in the maize production process. Based on the national statistics from 2016 to 2022, the changes of maize planting area, yield, production costs and mechanization level in the southwest hilly area were analyzed through multiple regression. The grey correlation method was used to analyze the influence of production costs and mechanization level of maize planting on its economic efficiency, and the relationship between comprehensive mechanization rate and cost profit margin was predicted by the ridge regression model. The results show that (1) In addition to the planting area, the maize yield, production costs and mechanization level in the southwest hilly area showed an overall upward trend, among which the net profit was negative for six consecutive years, mainly because the labor costs accounted for too much of the total costs; (2) The average annual increase in the level of maize mechanization is 16%, but it is still lower than the national average; (3) Under the condition that other factors remain unchanged, for every 1% increase in the comprehensive mechanization rate, the cost profit margin increases by 0.467%, and it is determined that the most important factors affecting the growth of maize production economic efficiency are the sowing rate and the yield rate. It put forward suggestions to strengthen the mechanization of maize planting and develop maize agricultural harvesting machinery suitable for the hilly area.

1. Introduction

The fundamental way out of agriculture lies in agricultural mechanization, and the green development of agricultural mechanization is an important driving force for sustainable rural development. With population growth and economic development, the demand for food is increasing. And agricultural mechanization can meet the growing demand for food by improving production efficiency and reducing production costs. At the same time, mechanized production can also promote the scale and intensive development of agricultural production, which is conducive to the rational allocation and efficient use of agricultural resources. All of this helps to promote the sustainable development of agriculture. Maize, as China’s first major food crop, but also the main raw material for feed and industry in China, plays a vital role in ensuring food security. Due to the rapid development of feed and deep-processing industries, the consumption of deep-processed industrial products using maize as raw material has increased, and the social demand for, and market supply pressure on, maize have been increasing [1]. Maize production economic efficiency can be significantly improved by increasing investment in agricultural mechanization [2], and in 2021, the national comprehensive mechanization rate of maize cultivation, planting and harvesting reached 90%. In the southwest hilly area, including the Sichuan, Yunnan, Guizhou and Chongqing provinces [3], the average annual maize production area is more than 4.67 million hectares, accounting for about 15% of the national maize production area, and it is one of the main maize-producing areas in the country, but its comprehensive mechanization rate is 34%, and the machine seeding rate and the machine harvesting rate are both less than 7%, which is much lower than the national average level, and this problem restricts the improvement of maize production in the southwest area. Qiao et al. [4] understood the influencing factors constraining agricultural mechanization and identified positive initiatives by examining the relationship between cotton production and farm machinery in China, suggesting that assessing the impact of agricultural mechanization will provide decision makers with suitable options for designing better policy tools.

In recent years, the increase in the contribution of agricultural machinery inputs has been the most significant structural change in the input factors of food production in China, so many scholars have explored the relationship between agricultural mechanization and crop production efficiency. Zhang et al. [5] analyzed the relationship between agricultural mechanization and crop yield through regression analysis, causality tests and other methods, and found that the total power of agricultural machinery promotes crop yield more significantly. Wu et al. [6] studied the threshold effect and spatial spillover effect of the level of agricultural mechanization on food production, proving that due to the inter-regional operation of agricultural machinery, the increase in the mechanization level in one region will significantly promote food production in its surrounding regions. Furthermore, for the relationship between agricultural mechanization and maize production efficiency, Zhang et al. [7] selected Henan Province as the research object, analyzed the impact of different constituent indicators of agricultural mechanization on the production of major grain crops, and found that the grey correlation between maize and agricultural mechanization is large. Dede et al. and Pan et al. [8,9], based on the empirical analysis of the provincial-level panel data of the main maize producing area in China from 2004 to 2017, found that agricultural mechanization has a significant impact on maize production efficiency, and mechanization has a significant positive effect on maize productivity. Isaak et al. [10] described the mechanization status of maize production in Malaysia based on the mechanization index of machinery and manpower consumption as the basis of evaluation, and concluded that the improvement in maize productivity needs to be achieved by the development of agricultural mechanization. The above studies have provided a preliminary understanding of the relationship between agricultural mechanization and maize production economic efficiency, and, in general, agricultural mechanization contributes to maize production economic efficiency. However, due to the differences in economic development conditions, institutional arrangements and geographic heterogeneity, the contribution of agricultural mechanization to maize production economic efficiency needs to be further analyzed and predicted quantitatively in terms of production economic efficiency, cost structure, net production profit, etc. Therefore, this paper takes the southwestern area as an example of modelling the relationship between its agricultural mechanization and maize production economic efficiency.

This study extends previous research and makes some breakthroughs. First, the southwest hilly area has special geomorphology, large slopes, small plots and sloping land slopes between about 3°and 20°; most of the cultivated plots are between 0.20 and 0.33 ha (3–5 acres). Yu et al. [11] found that most of them are using small-powered agricultural machines. This paper innovatively chooses the comprehensive mechanization rate of crop cultivation and harvesting as the main measurement index, which can more accurately reflect the mechanization of maize production in the southwest hilly area. In addition, with the implementation of the National Planting Industry Structural Adjustment Plan (2016–2020) and the ‘14th Five-Year Plan’ National Planting Industry Development [12], the implementation of the ‘Opinions on Doing a Good Job of Comprehensively Promoting the Key Work of Revitalization of the Rural Work in 2023’, based on the latest national policy changes [13], combined with policy influencing factors, we selected the data of 2016–2022 of the cost-effectiveness of planting maize in the southwestern hilly area, analyzed the cost composition of maize production and the trend of change, and explored the relationship between the development of the degree of maize mechanization and the benefits, which provided visual reference data for the new period of coordinating the maize machinery production planning in the southwestern hilly area. Second, based on the establishment of the grey correlation model, a ridge regression model was applied, which not only provided a clear picture of the development of maize production, but also a clear picture of the development of maize production. Third, based on the establishment of the grey correlation model, the ridge regression model was used to not only analyze the impact of the production cost of maize planting and the level of mechanization on its benefits, but also to predict the relationship between the two, which is of practical importance for improving the economic efficiency of maize mechanization and promoting the sustainable development of agriculture.

2. Research Methodology and Data Sources

In this paper, the costs and returns of maize cultivation in the southwestern hilly area and nationwide in 2016–2022 are studied, and all the data are obtained from the Compilation of National Agricultural Products Costs and Returns Data (2017–2023) compiled by the Price Department of the National Development and Reform Commission, the China Agricultural Machinery Industry Yearbook (2017–2022), the China Statistical Yearbook and the National Bureau of Statistics. The standards used in the relevant statistics are consistent with the National Compendium of Agricultural Product Cost and Benefit Information, and the calculation of each indicator of maize production costs is consistent with the algorithm used in the National Compendium of Agricultural Product Cost and Benefit Information.

The statistical analysis method, the comparative analysis method and Origin2018 software were used to draw graphs reflecting the situation of maize production economic efficiency in the southwestern hilly area.

The grey correlation analysis method was used to select the data of maize planting economic efficiency in the southwestern hilly area from 2016 to 2021 as the reference series, and the land costs y₀₁, labor costs y₀₂, seed, pesticide and fertilizer costs y₀₃, agricultural machinery costs y₀₄, mechanized cultivation rate y₀₅, mechanized seeding rate y₀₆ and mechanized harvesting rate data y₀₇ were selected as the comparative sequences in the cultivation of maize in the southwestern hilly area from 2016 to 2021. After using Microsoft Exce1 2016 for data processing, SPSS27.0 was used to conduct grey correlation analysis, and the specific steps of grey correlation analysis are found in Xing, Fan and Xu [14,15,16].

The ridge regression analysis method uses stepwise regression to further screen the indicators of factors affecting the mechanization rate of maize planting, substituting the data of various costs and net profit margins of maize planting in the provinces of the southwestern hilly area from 2016 to 2021, and using SPSS27.0 to carry out the stepwise regression analysis, the F-test and the T-test. The specific steps of the ridge regression analysis refer to the research results of Wegi and Yang [17,18].

3. Results and Discussions

3.1. Analysis of the Economic Benefits of Maize

3.1.1. Analysis of Maize Planting Area and Production

According to the China Statistical Yearbook (2017–2023), in the recent six years, the maize planting area changes in the southwest hilly area are shown in Figure 1a. As can be seen from Figure 1b, the nationwide maize planting area is in a stable and unchanged state, while the maize planting area in the southwestern hilly area shows a trend of first decreasing and then increasing. From 2016, due to the impact of the withdrawal of the temporary storage policy, the planting area slightly decreases, to 2020, when the temporarily stored maize is exhausted, the demand for maize increases, and the planting area resumes growth in 2021. As can be seen from Figure 1a, in Guizhou Province in 2018, the planted area decreased by 40.17% year-on-year; the first main reason for this is that one of the main measures of the National Planting Industry Structural Adjustment Plan (2016–2020) is to appropriately reduce the area of maize planting in non-advantageous zones, and Guizhou is precisely one of the maize planting areas in a non-advantageous zone. The second main reason is the adjustment of the state’s policy, which makes the subsidy for planting soybeans higher than the subsidy for maize. Then, for three consecutive years, the maize planting area continued to decline, and by 2021, the domestic temporarily stored maize was consumed, the maize deep processing and feed demand increased, and the maize planting area increased by 9.75%. By the national and Southwest Hills maize planting area regression analysis, Figure 1b shows that, in the next few years, the maize planting area will maintain the trend of restorative growth.

Figure 2b shows that the nationwide maize production shows a trend of decline followed by an increase. The trend of maize production in the southwest hilly area is the same, consistent with the change of maize planting area in the southwest hilly area, with an increase of 2.67%. Figure 2a shows that in 2018, the yield of Guizhou decreased by 41.30% year-on-year, mainly due to the significant reduction in planting area and agricultural disasters [19,20]. Due to the implementation of the National Agricultural Modernization Plan (2016–2020), which has improved the agricultural mechanization level, and the downward trend of production slowed down. Sichuan Province has introduced the Strategic Plan for Rural Revitalization (2018–2022) and other related policies to accelerate the transformation and upgrading of agricultural machinery and equipment and agricultural mechanization, and, as the planted area of maize is gradually decreasing, the yield is gradually increasing, with a rise of 2.5%. This shows that the increase in the level of agricultural mechanization has contributed to maize yield.

3.1.2. Characterization of the Cost Structure of Maize Cultivation

Referring to the “National Compendium of Cost and Benefit Information of Agricultural Products (2017–2022)”, the costs of maize production were analyzed in terms of three indicators: land costs, labor costs and material and service costs. Among them [21,22,23], the land cost includes the rent of transferred land and the discounted rent of self-owned land; the labor costs include the discounted price of household labor and the costs of hired labor; and the material and service costs refer to the analysis method of [24] to analyze the maize production costs in terms of the indicators of agricultural machinery/seeds, pesticides and fertilizers.

As shown in Figure 3a, in Guizhou Province after 2018, the costs of land continued to decline to 18%, mainly due to the implementation of the planting structure adjustment plan to reduce the planting area and the corresponding rent reduction. As shown in Figure 4a, after 2019, the costs of agricultural machinery decreased by 10%, which is due to the implementation of the Opinions on Accelerating the Implement of Agricultural Mechanization and the Transformation and Upgrading of Agricultural Machinery and Equipment Industry [25,26,27], and the implementation of the Opinions on Accelerating the Implementation of Agricultural Mechanization and the Transformation and Upgrading of Agricultural Machinery and Equipment Industry, which promoted the promotion of agricultural machinery in Guizhou Province in 2019, which led to a decrease in the costs of machinery leasing.

The change in the costs of agricultural machinery in Chongqing showed an inverted W-shaped change, decreasing by 14% year-on-year in 2018, as shown in Figure 4a. This is due to the implementation of the ‘Key Technology Promotion Action Program for Promoting the Full and Comprehensive Development of Agricultural Mechanization in 2018’, the promotion of agricultural mechanization technology in deeply impoverished areas, and the implementation of precision poverty alleviation, which led to a decrease in the costs of agricultural machinery. In the same year, it was as a result of this that the prevalence of agricultural machinery increased and labor costs fell, as shown in Figure 4a; however, due to the implementation of the Implementing Opinions on Accelerating the Transformation and Upgrading of Agricultural Mechanization and Agricultural Machinery and Equipment Industry, which led to the renovation and upgrading of agricultural machinery [28,29]. The costs of agricultural machinery rose by 18% in 2019. This is similar to the upward trend in the nation and the Southwest, Figure 4b.

In Figure 5a, it can be seen that in Yunnan Province, seed pesticide and fertilizer costs are much higher than in other provinces. More than 80% of the maize production is in the mountainous area at a higher altitude; the maize varieties require more inputs as a result. In Sichuan Province, seed pesticide and fertilizer costs decline by 3% in 2020 because of the abundant maize stocks and the general reduction of seed prices due to supply and demand. For 19 years, seed pesticide and fertilizer costs in Chongqing have been higher than in Sichuan, due to the higher proportion of maize breeding inputs in Chongqing, such as ‘Yuan 8’, ‘Yuno 7’ and ‘Yuno 918’. Seed pesticide and fertilizer costs in Guizhou province will continue to rise beyond 2020, even surpassing those of Chongqing, as the province’s unique karst landscape will require even greater efforts to develop a ‘seed industry invigorate’ and increase the cost of maize breeding inputs.

Overall, it can be seen from Figure 1, Figure 2, Figure 3, Figure 4, Figure 5 and Figure 6 that all the costs of growing maize are higher nationwide than in the southwestern hilly area. Figure 3b shows that the costs of land to grow maize nationwide are expected to continue to increase in the future. Figure 5b and Figure 6b reflect the same trend of labor costs and seed, pesticide and fertilizer costs for growing maize nationwide and in the southwestern hilly area.

As can be seen from Figure 7, from 2016 to 2022, the total costs of maize production in the southwest hilly areas continued to rise, with an average annual increase of 0.28%. The proportion of labor costs to seed, pesticide and fertilizer costs for producing maize is large, with the highest shares of 68% and 18%, respectively. Due to the implementation of the National Agricultural Modernization Plan (2016–2020), the promotion of agricultural machinery, and the replacement of agricultural labor by agricultural mechanization, the labor costs are on a downward trend year by year, but still currently account for the highest proportion [30,31]. In the period from 2016 to 2022, costs were affected by rising prices of raw materials for fertilizer and pesticide production and tightening domestic supply; the costs of seeds, pesticides and fertilizers increased year by year, and the proportion of the cost of seed, pesticides and fertilizers increased from 16% to 18%. The costs of land increased by 7.8%, mainly due to the development of urbanization in China, the reduction of rural labor, the costs of farmland subletting increasing, and the costs of land increasing, as shown in Figure 5b.

3.1.3. Analysis of Changes in Net Profit of Maize Production in the Southwest Hilly Area

As can be seen from Figure 8a, the overall trend in changes in net profit of maize production in the southwestern hilly area from 2016–2022 continues to rise, increasing by 56.4%. In Sichuan Province, the selling price of maize decreased and the total costs increased from 2016 to 2018, so the net profit of planting maize decreased first and then increased. The remaining three provinces had negative net profits for six consecutive years, as the growth of total costs was greater than the rate of production value, and as shown in Figure 7, the largest share of total costs in the southwestern hilly area was labor costs, which was 68%. After comparing, for example, the selling price of maize in the southwestern hilly area from 2016–2022 shown in Figure 8b, it can be concluded that the net profit has been negative for six consecutive years, mainly due to excessive labor costs.

3.2. Relationship between Maize Mechanization and Economics Efficiency

3.2.1. Analysis of the Degree of Mechanization of Maize Production

The comprehensive mechanization rate of crop ploughing, planting and harvesting in the standard of NY/T 1766–2019 Statistical Basic Indicators of Agricultural Mechanization is selected to reflect the degree of agricultural mechanization [32,33,34]. As can be seen from

Table 1. Efficiency of maize mechanization 2016–2021. Source: Data from The China Agricultural Machinery Industry Yearbook (2017–2022) and the National Agricultural Mechanization Development Bulletin and the National Bureau of Statistics.

Year	Nationwide				Southwest Hilly Area
	Comprehensive Mechanization Rate (%)	Mechanized Cultivation Rate (%)	Mechanized Seeding Rate (%)	Mechanized HarvestingRate (%)	Comprehensive Mechanization Rate (%)	Mechanized Cultivation rate (%)	Mechanized Seeding Rate (%)	Mechanized Harvesting Rate (%)
2016	69	74	70	62	18	44	1	1
2017	86	97	85	71	21	51	2	2
2018	88	97	89	76	24	57	3	3
2019	89	98	89	77	30	68	4	4
2020	90	98	90	79	31	70	5	5
2021	90	98	90	79	34	76	6	7

and

Table 2. Maize production efficiency factors in the southwest hilly area 2016–2021. Source: Data from Compilation of National Agricultural Products Costs and Returns Data (2017–2023) and The China Agricultural Machinery Industry Yearbook (2017–2022).

Evaluation Unit	Relatedness	Rankings
Mechanized harvesting rate	0.845	1
Mechanized seeding rate	0.809	2
Seed pesticide and fertilizer costs	0.798	3
Mechanized cultivation rate	0.782	4
Land costs	0.731	5
Labor costs	0.608	6
Agricultural machinery costs	0.46	7

and Figure 9a, the comprehensive mechanization rate of maize from 2016–2021 shows an upward trend. The comprehensive mechanization rate of maize in the southwestern hilly area grows from 18% in 2016 to 34% in 2021, and the mechanized cultivation rate grows from 44% in 2016 to 76% in 2021. However, there is little change in the rates of machine sowing and machine harvesting, which are 6% and 7% respectively by 2021 [35]. It is not difficult to find that the comprehensive mechanization rate in southwest China has always been lower than that of the whole country, because the maize planting area in China is divided into the Nouth area, Southwest hilly area and other areas. Among them, the mostly worthy comparison is that the maize region in the north has the highest degree of mechanization (95%), while the southwest area we studied has a low comprehensive mechanization rate of maize due to geomorphological reasons, and mechanized planting is dominated by micro-tillers, while the north uses more large machinery due to the flat terrain [36,37]. Figure 9b, the regression formula for the comprehensive mechanization rate of maize in the southwestern hilly area is

Y_J = 0.0007X²_J + 1.0393X_J + 0.138

(1)

where X_J is the probability of year and Y_J is the probability of comprehensive mechanization rate in the southwestern hilly area. The degree of maize mechanization in the southwestern hilly area is on an upward trend. The regression formula predicts that the mechanization rate is expected to reach 55% in 2025 and 75% in 2035.

3.2.2. Impacts and Projections of Production Costs and Mechanization Levels in Southwest China

The degree of correlation between each influencing factor and maize production efficiency is difficult to analyze using traditional regression analysis [38,39], so the grey correlation method was chosen to analyze the relationship between maize production efficiency and influencing factors in the southwest hilly area, to determine the importance of each influencing factor and provide a basis for seeking to improve the efficiency of maize production in the southwest hilly area [40,41]. The results of grey correlation are as follows: Table 2 shows that the factors that contribute to the magnitude of maize production efficiency are, in order of magnitude, Mechanized harvesting rate > Mechanized seeding rate > Seed pesticide and fertilizer costs > Mechanized cultivation rate > Land costs > Labor costs > Agricultural machinery costs. The Machine harvesting rate has the highest correlation with maize production efficiency, with a correlation degree of 0.845, and the lowest correlation is between Agricultural machinery costs and maize production efficiency.

The relationship between the comprehensive mechanization rate of maize production in the southwestern hilly area and the various costs and benefits can be obtained by using stepwise regression analysis, which shows that the four indicators that have a significant impact on maize cost margins in the southwestern hilly area are the costs of land, the cost of labor, the cost of farm machinery, and integrated mechanization rate for maize [42,43]. To eliminate the multicollinearity between the respective variables, the method of ridge regression is used for regression analysis of the model [44,45], the Ridge regression method is to add K (bias coefficient) to the main diagonal element of the independent variable standardization matrix so that the regression coefficient estimator can maintain a much greater accuracy than the unbiased estimator under the condition of small deviation, which can significantly improve the stability of the estimation. The range of regression coefficient K was set between 0 and 1, and the data interval was 0.01. As shown in Figure 10. Change in ridge regression coefficients with increasing shrinkage parameter. When K ≥ 0.89, the regression coefficient of each variable tended to be stable, and the ridge regression model can be established. Among the factors affecting the production of maize in the southwestern hilly area of the integrated mechanization rate of maize, the costs of agricultural machinery and the costs of profitability have a significant positive correlation. With elasticity coefficients of 0.467 and 0.258, respectively, and all other factors remaining unchanged, for every 1% increase in the integrated mechanization rate, the cost of profitability increases by 0.467%. Therefore, to effectively increase the benefits of maize production, it is necessary to strengthen the development of maize production mechanization in the southwestern hilly area, and at the same time, it is still necessary to strengthen the investment in the research and development of agricultural machinery and equipment. The proportion of cost is the largest, with the highest proportion of 68%, so reducing labor costs can effectively reduce the total cost of planting maize in the southwestern hilly area, and replacing manual labor with farm machinery and equipment can effectively reduce labor costs [46,47].

4. Conclusions

Through the analysis of the changes in the costs of maize production and the degree of mechanization in the southwestern hilly area, the following conclusions are drawn.

First, in 2016, by the withdrawal of the critical storage policy, the planting structure adjustment and other impacts, although the maize planting area has been reduced, and the national planting area was first reduced and then increased, the degree of agricultural mechanization achieved savings in labor elements and increased the total maize production to the national average level of maize production. It can be seen that the increase in the rate of agricultural mechanization plays a contributing role in the yield of maize.

Second, the total costs of production of maize show a rising trend year by year; the net profit increased by 56.4%; and the labor costs accounted for the largest proportion of the total costs, at 68%; so reducing the labor costs can effectively reduce the total costs of planting maize in the southwestern hilly area, and replacing manual labor with agricultural machinery and equipment can effectively reduce the costs of labor. The ridge regression model yields that, with other factors remaining unchanged, every 1% increase in the comprehensive mechanization rate of maize production can increase the cost margin by 0.467%.

Third, through the grey correlation method and ridge regression analysis, it can be obtained that the machine sowing rate and machine harvesting rate are the most important factors affecting the growth of maize production efficiency, and accelerating the mechanization of maize sowing and harvesting can effectively improve maize production efficiency.