1. Introduction
Food security has been jeopardized by several linked variables, including population increase, environmental issues, and land degradation. It is predicted that the world’s population will reach around 10 billion by 2100 [
1]. Indeed, China is the world’s most populated nation, feeding one-fifth of the world’s people while utilizing just 8% of the world’s agricultural land [
2]. The Chinese government’s long-term aim is to provide foods for the country’s rapidly rising population. Furthermore, food consumption will continue to rise due to population expansion and economic development. However, arable land and other productive resources will diminish due to climate change’s impact on agricultural production [
3,
4]. For China to achieve food security by 2030, China’s grain production must rise by an estimated 142% while having just 85% of its existing cropland [
5]. Hence, technical progress is essential for sustainable agricultural production in the country.
Technology has long caught the attention of economists and economic historians as the key to long-term economic development. Contemporary economic growth theory demonstrates that technological progress should be the primary driver of long-term economic growth. This means that China’s agricultural development should be driven by advances in technical change/progress rather than traditional factor input growth, which are the government’s primary aims [
6]. Over the last three decades, advancements in agricultural technology have been the primary driving factor behind increases in wheat, rice, and corn yields in major crop-producing nations [
7]. A significant contribution to increasing food crop yields in China has come from the rapid development of agricultural biochemistry technology, mechanical technology, and cultivation technology.
In addition, chemical fertilizers and large agricultural machinery are used in the construction of irrigation and water conservation facilities, which have been integral in increasing crop yields. Nonetheless, several hurdles to boosting agrarian productivity to fulfill this need include increased food consumption and land and water resources [
8]. A study by Huang et al. [
9] predicts that China’s total food self-sufficiency will likely decline from 94.5 percent in 2015 to roughly 91 percent by 2025.
Climate change is projected to exacerbate China’s food security concerns. China’s yearly average temperature has been steadily increasing over the last six decades, and the trend is expected to continue [
10]. According to scientific studies and observation data, climate change has substantially influenced China’s agriculture and crop yields, such as wheat, maize, and rice [
11]. It is well acknowledged that the primary mechanism of climate change influencing China’s agriculture is the increase in temperature and the increase in variability of precipitation [
12].
A growing body of research indicates that crop yields in arid and semi-arid areas are disproportionately impacted by climate change, notably via aridification, which severely hinders agricultural expansion in these places [
13]. With a total planting area of 30,190 hectares, China produced 148.5 million tons of cereals in 2018, making it the world’s biggest cereal producer and accounting for around 28% of global production [
14]. With 20–36 percent in the next 20–80 years, its grain yield is predictable to decrease because of climate change [
15]. The unusual changes in temperature and rainfall can slow down the growth of food crops, resulting in a drop in the average yield of grains [
16].
Numerous studies have shown that climate change dramatically lowers the production potential of various crops at various sizes (i.e., global, regional, and local scales). For example, between 1980 and 2008, the worldwide production potentials of wheat and maize were lowered by around 6% and 4%, respectively. Climate change enhanced the Fertile Crescent’s wheat production potential in Asia [
17] and decreased rice and wheat production potential in the upper Indian Ganga Basin [
18]. In China, output potential was lowered in the Northeastern region by 6.45 percent due to a hotter environment and less precipitation [
18].
Sichuan province is the leading agricultural province and the only central grain-producing province in Southwest China. In 2018, the grain production of Sichuan province reached 34.937 million tons, including 14.786 million tons of cereal, 2.473 million tons of wheat, and 10.663 million tons of corn [
19]. The trends of food crop production and the sown area are shown in
Figure 1. Cereals are the most significant food in the province, independent of the land under cultivation or the total amount of grain produced. Recently, the area where cereals are grown has stabilized. However, the area planted with wheat has dropped by almost half in the last decade, and the area planted with corn has fallen by nearly half in the same time. The climatic condition has also changed, typically exhibiting higher temperature characteristics and less precipitation. This is also induced by the rise in CO
2 emissions reported in the province annually [
2].
Changes in temperature and rainfall are important indicators that show how the climate changes. In the last 50 years, from 1960 to 2013, the surface air temperature in China has risen by 0.27 °C every 10 years. This is faster than the rate of warming in the rest of the world and in the northern hemisphere over the same period. Also, the average precipitation that falls annually across the country is rising [
21]. Most provinces in China have trouble growing food crops because of changes in temperature and rainfall. This causes the average grain yield to go down [
1]. Sichuan province’s average temperature in 2019 was 15.4 °C, which is 0.5 °C higher than the average temperature for the year. This is the ninth highest average temperature in history. At the same time, it rains less during the year, which shows that rain unevenly falls in Sichuan province [
1].
Figure 2 shows the trends of temperature and rainfall changes in Sichuan province from 1980–2018.
The present paper explores how technical factors (i.e., fertilizers use and mechanization) and climate change (via temperature and rainfall) impact the production of staple food crops (i.e., rice, wheat, and corn) in Sichuan province by using the GMM approach.
3. Data and Methodology
This study examined the impact of technological progress and meteorological factors on major food crop production in Sichuan province, China (see
Figure 3). In order to accomplish the core objective of this study, the annual time-series data-set spanning between 1980 and 2018 was accessed from the Sichuan Statistical Yearbook and China Rural Statistical Yearbook [
20]. We considered the following variables for the estimation: major food crop production, which included rice production (10,000 tons per hectare), wheat production (10,000 tons per hectare), and maize production (10,000 tons per hectare). Technical factors include fertilizers used (10,000 tons per hectare) and mechanical farming rate (%). Further, this study considers climatological factors such as mean annual temperature (Celsius) and mean annual rainfall (mm) and also includes other vital determinants such as rice sown area (10,000 hectares), wheat planted area (10,000 hectares), maize sown area (10,000 hectares), agricultural credit (100 million RMB), and agrarian labor (10,000 persons). The trend of the studied variables is shown in
Figure 4.
Previous studies used several research techniques to estimate the time series and the panel data-set. However, following existing literature [
52,
53], the current study uses the generalized method of moments (GMM) technique to assess the impact of technological progress and climatological factors on major food crop production. As in this study, we use annual time-series data and apply the GMM. The GMM estimator helps us resolve the possible endogeneity issues in our data-set. This approach (GMM) provides more robust and reliable outcomes than non-instrumental methodologies [
54]; however, further instruments added in this method are found to reduce the sample size of the time-series as well as panel data-set [
55]. The GMM is one of the most suitable methods in the nexus of climatic variables and agriculture production [
52,
53]. To achieve our main objective, we have taken the primary form of major food crops production which can be written as:
Model I: The impact of technological progress and meteorological factors on rice production
Model II: The impact of technological progress and meteorological factors on wheat production
Model III: The impact of technological progress and meteorological factors on maize production
Using the GMM, we have re-formulated the Equations (1)–(3) into natural logarithm as:
where
Rice = rice production,
Wheat = wheat production,
Maize = maize production,
Fer = fertilizers used,
Mech = mechanization,
Temp = temperature,
Rf = rainfall,
Rsa,
Wsa, and
Msa = sown area of major food crops (i.e., rice, wheat, and maize),
Acr = agricultural credit,
Rl = rural labor,
t = time period (1980 to 2018),
ln = for natural logarithm, and
= the error term.
4. Results and Discussions
Table 3 provides the summary of the variables that were studied. The estimated statistics of all considered variables reveal that primary food crop production (i.e., rice, wheat, and maize) exhibits +ve mean values, surpassing their standard deviations. Further, this study observed the highest (7.831) and lowest mean value (0.306) in rural labor and mechanization. Except for rice production, all the underlying variables have a Kurtosis value smaller than three. In addition, other variables are generally distributed as per the +ve sign and −ve sign of Skewness.
Figure 5 show a summary of descriptive statistics.
Agricultural production and climatic variability are interrelated in various ways because continuous climate change is the prime cause of biotic and abiotic stresses that adversely affect crop production globally [
56]. In China, rice (
Oryza sativa) and wheat (
Triticum aestivum L.) are produced mainly and consumed as the main staple foods by its teeming population.
Table 4 shows the effect of technical progress and meteorological factors on rice output in Sichuan province from 1980 to 2018. Based on the empirical findings of Model (1), at the 1% significance level, increased fertilizer consumption is related to higher rice yield. This result corroborated the assertion of Chandio et al. [
29] and Pickson et al. [
37], who concluded that fertilizer utilization positively contributed to rice yields in the case of Nepal, Pakistan, and China, correspondingly. Similarly, mechanization has a positive and significant effect on the rice yield of Sichuan province at the 1% level, hence approving the Hypothesis
(H1). This result agrees with the findings of Zhou and Ma [
57], who used data from 29 provinces in China and showed the positive nexus between mechanization and farming productivity.
Furthermore, in the case of Nigeria, Takeshima et al. [
58], and in the context of sub-Saharan Africa, South Asia, and Latin America, Van Loon et al. [
59] revealed that mechanized farming had higher crop productivity. The temperature, in contrast, is significantly and negatively related to rice production at the 10% level, thus endorsing the Hypothesis
(H2). This means higher average temperature brings about lower rice output in Sichuan province. This result is congruent with Bhardwaj et al. [
42] and Gul et al. [
34], who reported that increased temperature had a detrimental effect on rice cultivation in India, Thailand, and Pakistan.
This finding also backed up the claim of Wang et al. [
11], Li et al. [
60], and Pickson et al. [
37], who found that climate factors adversely and significantly affected rice production in China. As rice is one of the primary crops in China [
51], the negative effect of global warming on rice crops suggests that the food security in China is currently threatened. Rainfall, however, did not affect the rice production of Sichuan province during the investigated period. Thus, consistent with the result of Ali et al. [
36], there is no association between precipitation and rice yield. At the 1% significance level, the empirical finding of Model (1) likewise suggests a positive relationship between rural labor and rice production. The findings from the GMM method for Model 1 are displayed in
Figure 6.
Table 4.
The effect of technical progress and climate change on rice productivity (Model 1).
Table 4.
The effect of technical progress and climate change on rice productivity (Model 1).
Variables | Coefficient | Std. Error | t-Statistic | Prob. |
---|
_Cons | −2.881607 | 1.784180 | −1.615087 | 0.1168 |
lnRP (−1) | 0.246357 | 0.113660 | 2.167498 | 0.0383 |
lnFER | 0.259965 | 0.085917 | 3.025749 | 0.0051 |
MECH | 0.623438 | 0.166159 | 3.752058 | 0.0008 |
lnTEMP | −0.486761 | 0.277146 | −1.756333 | 0.0892 |
lnRF | 0.038773 | 0.114849 | 0.337600 | 0.7380 |
lnRSA | 0.129937 | 0.412785 | 0.314782 | 0.7551 |
lnACR | −0.034713 | 0.025730 | −1.349087 | 0.1874 |
lnRL | 0.931849 | 0.226162 | 4.120273 | 0.0003 |
R2 | 0.773248 | | Adjusted R2 | 0.712781 |
D-W stat | 1.414508 | | J-stat | 2.143243 |
Sustainable and healthy food production is essential to fulfilling the domestic food demand of the rapidly growing population. Hence, the farming sector needs to optimize the technical progress to achieve this goal and improve green economic growth. Winter wheat is commonly cultivated in several Chinese provinces. However, some provinces grow winter and spring wheat based on suitable climatic conditions and achieve higher yields. Although Sichuan province also produces winter wheat, the production is lower as compared to other wheat-producing provinces.
Regarding the effects of farming techniques and weather conditions on wheat production in Sichuan province, the empirical results in
Table 5 demonstrate that fertilizer utilization positively affects wheat production at the 5% significance level; consequently, we confirm the Hypothesis
(H1) of our study. This result affirms Ali et al.’s [
38] findings that fertilizer usage significantly increases wheat output. Temperature, in contrast, adversely impacts wheat production at the 1% significance level, implying the unwanted effect of climate change on wheat production in Sichuan province; as a result, we confirm the Hypothesis
(H2) of our study. Since wheat is the second major crop in China that contributes significantly to the national food security [
61], this result indicates a severe issue of climate change that dramatically affects food security in China. This result supports Huang et al. [
9], Ali et al. [
38], and Bhardwaj et al. [
42], who figure out the adverse relationships between temperature and wheat yields in China, Pakistan, and India, respectively. Additionally,
Table 5 demonstrates that wheat production is significantly affected by the rural labor in Sichuan province. The outcomes from the GMM technique for Model 2 are also demonstrated in
Figure 6.
Presently, maize (
Zea mays L.) is widely grown as a food crop around the globe, and it covers 193.7 million hectares of planting area with an annual production of 1147.6 million tons [
62]. In Sichuan, the maize crop is also extensively grown and considerably contributes to the livestock industry.
Table 6 exhibits the significant and positive influence of fertilizer usage and mechanical farming rate on maize yields at the 1% and 5% significance levels; hence, it is noteworthy to confirm the Hypothesis
(H1) of this investigation. The results signify a vital role of technical progress in maize production in Sichuan province. These results are similar to the conclusions of Chandio et al. [
30] and Zhou et al. [
63] that usage of fertilizer and farm machinery positively impacts maize production in Nepal and China correspondingly. However, the climate changes with temperature and rainfall factors negatively affected maize yields in Sichuan province during the investigated period; consequently, we endorse the Hypothesis
(H2) of this investigation. This finding is congruent with maize’s feature that it can withstand moderate to high temperatures [
64,
65]. The result on the temperature-maize production nexus is negative but non-significant, while in previous findings, the temperature is significantly and negatively associated with rice and wheat crop yields, suggesting that maize could be an alternative to rice and wheat under ongoing climate change. In
Table 6, agricultural credit negatively and significantly decreases maize production, implying the ineffectiveness of using credit in developing maize crops. Finally,
Figure 6 shows the overall results of the GMM approach for models 1, 2, and 3.
5. Conclusions
Being a significant grain-producing province in western China, Sichuan supplies substantial cereal outputs to the country. This region, however, has experienced a marked change in climatic conditions that exhibit a higher average temperature and less precipitation. Therefore, this study scrutinized the impacts of technical progress (fertilizer use and mechanization) and climate change (temperature and rainfall) on major food crops’ output to reveal the determinants of food crop outputs in Sichuan province.
Overall, farming techniques and meteorological factors heterogeneously influence major crop productions in Sichuan province. Specifically, our empirical results reveal the positive nexus between fertilizer utilization and outputs of all major crops (rice, wheat, and corn). Regarding mechanization, only rice and corn yields are significantly and positively impacted. In terms of climatic factors, increased average temperature greatly diminishes rice and wheat yields, suggesting the threat of climate change to the food security of Sichuan province and China. Rainfall, nevertheless, is unlikely to have a significant effect on any crop production in Sichuan province. In addition, rural labor contributes positively to major food crops in Sichuan province.
5.1. Policy Implications
According to the empirical findings, our study proposes several recommendations to enhance the current major crop production in Sichuan province and ensure food security in China. First, the effectiveness of using fertilizer is evident in Sichuan province’s primary food crop production. Hence, applying quality fertilizers with recommended doses is critical to achieving higher rice, wheat, and corn outputs in the region. Second, mechanization also plays an essential role in increasing food crop production. Therefore, the use of technology in food crop cultivation should be vigorously promoted.
Finally, due to the current level of global warming and its effect on food production in the country, China’s government should consider revising its strategies and policies to reduce the impact of climate change on food crop production and increase the adaptive ability of farmers. In particular, there should be a provincial program to improve the quality of cultivation areas with a better irrigation system. The farmers also need to be supported to select cultivars suitable for higher temperatures and adopt climate-resilient agricultural technology that brings about long-term food security for the region and the whole country.
5.2. Limitation and Future Research Path
Achieving sustainable food production and green economic growth is a prime objective of the Chinese government. Hence, the current study used annual time-series data from 1980 to 2018 and applied the GMM approach to examine the impacts of climatic changes (via an average yearly temperature and an average annual rainfall) on the top three main staple food crops, rice, wheat, and maize production of Sichuan Province-China. The key findings revealed that climate change adversely influences primary food crop production. Moreover, this study suggests that academicians and researchers may consider the seasonal minimum and maximum temperature and precipitation level to assess the climate change impacts on food crop yield and incorporate the influential role of crop-wise chemical fertilizers use, agricultural machinery, and public policy support programs in major food crops producing provinces of China by using a panel database.