Application of Conservation Tillage in China: A Method to Improve Climate Resilience

Abstract

In the context of climate change, agricultural cultivation, as one of the most vulnerable sectors, is under threat. Extreme weather and climate conditions have caused a series of problems, such as yield loss, more serious pests and diseases, and declining biodiversity. Conservation tillage is considered a potential method to improve climate resilience, yet the intrinsic mechanism of how conservation tillage functions to improve the climate resilience of agriculture is uncertain. Here, we performed document analysis to explore how conservation tillage stabilizes and increases crop yield and reduces greenhouse gases. We reviewed the definition of resilience and proposed the practice of conservation tillage. Our research found that conservation tillage has the potential of improving soil health and reducing greenhouse gases to enhance climate resilience. Although there is some evidence demonstrating that conservation tillage has a negative impact on crop yield and greenhouse gases, we still advocate the adoption of conservation tillage according to local conditions. We suggest that choosing proper practices, such as crop rotation, the use of cover crops, and holistic grazing, when used along with conservation tillage, can maximize the benefits of conservation tillage and alleviate the possible negative effects of this practice.

1. Introduction

According to the Synthesis Report of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report, the combined land and ocean globally averaged surface temperature increased by 0.85° over the period of 1880 to 2012 [1]. Moreover, the increase in temperature has resulted in a robust increase in extreme weather event indices and a series of detrimental effects on natural systems [2]. Climate change has a particularly significant impact on agricultural cultivation, due to its dependence on environmental factors. Weather and climate conditions such as droughts, flash floods, untimely rains, frosts, hail, and storms may cause a drop in agricultural production [3]. Because of intensive farming using conventional tillage practices, food production has shown a significant growth, which has decreased the proportion of human suffering from hunger [4]. Moreover, to this day, plowing and rotary tillage for land preparation is still commonly practiced by farmers. Such conventional tillage exacerbates soil disturbance and not only has a negative impact on soil health, but is also a bad option for increasing agricultural climate resilience.

Conservation tillage has been recognized as a potential method for increasing agricultural climate resilience. The Ministry of Agriculture and Rural Affairs of the People’s Republic of China advocates conservation tillage as a method to alleviate field dust, reduce soil erosion, protect soil fertility, and realize harmony between humans and nature [5]. We reviewed the concept of resilience and the different conservation tillage operations in China, the United States, the United Kingdom, the European Union, and Sub-Saharan Africa. It is explained how conservation tillage improves agriculture’s ability to maintain core functions in the face of climate change, and mitigate its negative impacts. Finally, we give some suggestions for promoting conservation tillage in China based on different regional characteristics.

2. Definitions of Climate Resilience and Conservation Tillage

Agriculture is one of the most sensitive sectors in response to climate change, and crop production is highly dependent on environmental factors. Therefore, the impact of climate change is particularly pronounced on crop production. Over recent years, climate change, mainly characterized by global warming, has changed the former environment of agricultural cultivation, coupled with the impact of extreme weather such as droughts, floods, and wind storms, which has brought about many impacts on crop production. Agriculture, as the foundation of human survival, has a significant influence on food security, industrial development, and social stability, and has received extensive attention due to its significant status. In response to the impact of climate change on agriculture, the concept of “climate resilience” has been introduced to help improve agriculture’s ability to cope with climate change.

Resilience is an umbrella term widely used in the academic community (Table 1). The term resilience was first used in physics or engineering to refer to the ability of a material or building to resist stress and disruption and its ability to recover after deformation [6]. The use of the term then gradually expanded to other disciplines. Holling [7] introduced the concept of resilience to the ecosystem and proposed that resilience determines the persistence of relationships within a system. It is an indicator to measure the ability of these systems to absorb changes in state variables, driving variables, and parameters, and still persist, thus enriching the connotation of resilience. Walker [8], from a social-ecological perspective, uses resilience to refer to the capacity of a system to absorb disturbances and reorganize when undergoing change in order to still retain essentially the same function, structure, identity, and feedbacks. When it comes to climate change, IPCC [9] defined resilience as the “ability of a system and its component parts to anticipate, absorb, accommodate, or recover from the effects of a hazardous event in a timely and efficient manner.” Furthermore, especially in agriculture, Daniel EI Chami believes that resilience refers to the capacity of agricultural systems to respond to social, economic, and environmental changes via structural reorganization, in order to offset the impacts of future changes, and to engage in new opportunities, to ensure the continuity of agrosystems [10].

In the context of climate challenges faced by agriculture, we argue that “climate resilience” refers to the ability to maintain agriculture’s core functions, including food security, soil and water conservation, and economic growth, while mitigating the impacts of climate change.

Conservation tillage is considered a potential way to improve the climate resilience of agriculture, so it is necessary to clarify exactly what conservation tillage entails. One of the most widely accepted definitions, from the Conservation Technology Information Centre (CTIC) [11], is “any tillage and planting system that covers 30% or more of the soil surface with crop residue, after planting, to reduce soil erosion by water.” Based on specific circumstances, different countries and regions have developed their own definitions of conservation tillage. In accordance with the relevant documents issued by the Ministry of Agriculture and Rural Affairs of the People’s Republic of China, conservation tillage is a modern farming technology system that mainly involves residue incorporation and no/reduced tillage [12]. The definition of conservation tillage by the United States Department of Agriculture is the same as that of the CTIC [13]. In the United Kingdom (UK), conservation tillage is commonly called non-inversion tillage [14]. The Department for Environment, Food, and Rural Affairs of the UK defines no-till farming by advising, “do not use cultivation machinery when you prepare the land for crops” [15]. According to Eurostat, conservation tillage refers to arable land treated by conservation (low) tillage, which is a tillage practice or practice system which leaves plant residues (at least 30%) on the soil surface for erosion control and moisture conservation, normally by not inverting the soil [16]. In Sub-Saharan Africa, soil nutrient depletion is an important constraint to sustainable agriculture development [17]. As a potential way to mitigate climate change and achieve sustainable agricultural development, Sasakawa Global 2000, an international non-governmental organization, introduced conservation tillage to Sub-Saharan Africa, and the main technical points advocated by Sasakawa Global 2000 are the non-interference with the soil and the retention of mulch through the non-reversing of the soil [18].

Above all, it is not difficult to see that crop residue and no-tillage are the core technologies of conservation tillage practice (Table 1). Therefore, we conclude that conservation tillage should refer to the agricultural production system with more than 30% crop residue and no-tillage as the basic operations that can improve the ability of agriculture to maintain its core functions and mitigate the impacts of climate change.

Table 1. Technical points of conservation tillage practice in different countries and regions.

Country/Region	Technical Points
China	residue incorporation, and no/reduced tillage [12]
United States	resilience determines the persistence of relationships within a more than 30% crop residue [13]
United Kingdom	not using cultivation machinery [15]
European Union	leave at least 30% plant residue and do not invert soil [16]
Sub-Saharan Africa	do not disturb the soil and allow retention of mulch [18].

Table 1. Technical points of conservation tillage practice in different countries and regions.

Country/Region	Technical Points
China	residue incorporation, and no/reduced tillage [12]
United States	resilience determines the persistence of relationships within a more than 30% crop residue [13]
United Kingdom	not using cultivation machinery [15]
European Union	leave at least 30% plant residue and do not invert soil [16]
Sub-Saharan Africa	do not disturb the soil and allow retention of mulch [18].

3. Conservation Tillage Can Improve Climate Resilience for Agriculture

Climate change is manifested by climate warming, abnormal precipitation, floods, droughts, wind storms, and other extreme weather, which cause a number of problems to agriculture, including disturbance to soil structure, loss of soil nutrients, decrease in biodiversity, plant diseases and pest outbreak, and low crop yield. We will explain how conservation tillage can function to enhance climate resilience by improving soil health from the aspect of water dynamics, soil physicochemical properties, and the eco-environment and by reducing greenhouse gases to mitigate the negative impact of climate change (Figure 1).

3.1. Conservation Tillage Can Improve the Hydrologic Function of Soil

Abnormal precipitation caused by climate change poses many problems for agriculture. Long-term precipitation or short-term but heavy precipitation often make it difficult for water to infiltrate, causing surface runoff, which eventually leads to flooding. Likewise, a long-term drought easily causes water shortages during the growing seasons of crops, leading to yield reduction. However, there are some cases to support the idea that conservation tillage has positive effects on soil hydrologic function. Xuan Yang [19], using APSIM (Agricultural Production Systems sIMulator)-based simulation modelling and data collected in Xifeng, Gansu, China, found that conservation tillage has better performance for soil water storage, reducing soil evaporation and reducing evapotranspiration, while only plant transpiration is greater compared with conventional tillage. Qi Zhang [20] conducted a long-term experiment in Ganjing, Heyang County, Shaanxi Province, China. This study showed that no-tillage reduced water consumption by 10.6% compared with conventional tillage over the entire growing season, and no-tillage could increase the water use efficiency as well. In particular, the water use efficiency of maize showed a significant improvement under a certain rainfall distribution showing poor rainfall in the jointing-tasseling stage and adequate rainfall in the grain filling-maturity stage. In addition, Juan li [21] (Li et al. 2020) also found that conservation tillage can increase water use efficiency in comparison to traditional rotary tillage in an experiment that was carried out in Fuping County, Shaanxi Province. Ziyou Su [22] found, in a six-year field experiment in Mengjin County, Luoyang City, Henan Province, China, that winter wheat with no tillage mulch had a greater amount of available water storage and higher water use efficiency. Conservation tillage is able to enhance water infiltration and reduce water evaporation, thus increasing soil water storage and improving water use efficiency, which gives agriculture higher resilience to cope with climate change.

3.2. Conservation Tillage Can Improve Soil Structure and Increase Soil Nutrients

Extreme weather is one of the manifestations of climate change, which has a negative impact on food production. Wind storms and heavy rain, for instance, tend to erode topsoil and rob soil of nutrients, thereby reducing crop yield. Fortunately, there is some evidence demonstrating that conservation tillage can mitigate the impact of climate change. Zhe Liu [23] conducted the study in Shaanxi Province, China, and the results indicated that conservation tillage can promote the increase in soil organic matter and total nitrogen content, and can improve soil structure as well. In a five-year experiment conducted in Weinan City, Shaanxi Province, China, Juan Li [21] observed that no-tillage was able to decrease soil bulk density. Rafiq Islam [24] had a similar finding at the David Brandt farm, Carroll, Ohio. The findings confirmed that soil bulk density decreased significantly at a 0 to 30-cm depth under long-term no tillage. Furthermore, no-tillage can increase soil aggregate stability. In addition, conservation tillage can increase soil nutrients. Besides soil bulk density, the research of Juan Li [21] also showed that continuous no-tillage increased soil organic carbon remarkably. R. Islam [24] found that no-tillage not only increases soil total carbon, but also increases soil total nitrogen and particulate organic matter. V. Kushwa [25] initiated a long-term experiment on a soybean-wheat cropping system and found that no tillage can increase soil organic carbon content and available phosphorus concentration. As for potassium, A. D. Karathanasis [26] observed that exchangeable and soluble K increased by two or three times after long-term no-tillage in western and central Kentucky, USA. Conservation tillage is beneficial for improving the soil’s physical and chemical properties. No-tillage reduces soil disturbance so that the soil structure can be improved and soil aggregate stability can be enhanced as well. Conservation tillage can increase soil nutrients through stubble mulching. In this way, conservation tillage mitigates the impact of climate change on agriculture and increases climate resilience.

3.3. Conservation Tillage Can Reduce Greenhouse Gases to Mitigate Climate Change

The IPCC [27] reported that 23% of total greenhouse gas emissions are derived from agriculture, forestry, and other land uses. The soil organic carbon pool is the largest organic carbon pool in terrestrial ecosystems [28]. Conservation tillage is considered one of the most promising potential methods to achieve soil carbon sequestration and reduce greenhouse gas emissions. One method of carbon sequestration by conservation tillage is to enhance soil aggregate stability, and the other method is to place soil organic carbon in the sub-soil horizons and incorporate it with biomass. The cementation of primary particles, clay domains, and micro-aggregates is based on the formation of organo-mineral complexes. These complexes bind clay into aggregates, thereby immobilizing and sequestering the carbon [29]. In terms of greenhouse gases emissions, numerous studies have shown that conservation tillage can reduce greenhouse gas emissions. Guo Zhang and Xiaoke Zhang [30] reviewed some new publications that report the impact of conservation tillage on the emission of greenhouse gas, carbon sequestration, and the global warming potential of greenhouse gas in China. The results indicated that conservation tillage can reduce greenhouse gas emission by considering carbon sequestration. Jinfei Feng [31] carried out a global meta-analysis based on 49 papers published before December 2016. The results showed that no-tillage significantly reduced the overall global warming potential of CH₄ and N₂O emissions by 6.6%, in comparison with conventional tillage. Yawen Huang [32] used the data from 90 publications between 1900 and 2017 to obtain similar results showing that no-tillage can reduce 15.5% of CH₄ emissions, which can reduce the global warming potential, under specific conditions.

3.4. Conservation Tillage Can Improve the Soil’s Eco-Envirnment to Achieve Weed and Pest Control

Climate change caused a rise in land-based temperature, which has a considerable impact on weeds and soil organisms. Climate change greatly affects the abundance of soil organisms, including fungi and nematodes, and created a suitable environment for weed growth and favorable conditions for pest diseases. Conservation tillage has a positive impact on soil health, providing a good living environment for soil organisms and increasing the abundance and species diversity in soil organisms. Ziting Wang [33] performed trials in Yangling, Shaanxi, China. The richness and diversity of soil bacteria were observed by the Shannon index and Simpson index. The results showed that conservation tillage increased the abundance of profitable functional bacteria species. Lijun Cai [34] also found that conservation tillage can improve soil bacterial richness and diversity after conducting a long-term experiment in Jiamusi, Heilongjiang, China. In addition, the results demonstrated that conservation tillage has the best performance in increasing soil bacterial richness and diversity under 60% residue mulching. In Dehui County, Jilin Province, China, Shixiu Zhang [35] compared the response of microflora and microfauna under different treatments. The results indicated that conservation tillage has a positive impact on the richness and abundance of bacteria.

The increase in the abundance and diversity of soil organisms, especially the natural enemies of pests, can achieve pests control. Meanwhile, conservation tillage can affect pathogens and predators to eliminate pests. The study that Shixiu Zhang [35] conducted in Jilin Province, China, confirmed that conservation tillage can build a more functionally stable food web. According to the assessment of Robert P. Jaques [36], entomopathogens have the potential to control pests. Ronald B. Hammond [37] proposed that conservation tillage is a useful practice for soybean growers to prevent soil pests due to its direct impact on arthropods, and cover crops have the same use as well. Giovanni Tamburini [38] conducted an experiment in Udine Province, northeast Italy. The study showed that conservation tillage is able to increase the abundance of predator communities and support higher aphid predation (rate). Compared with conventional tillage, conservation tillage can provide better biological pest control and can easily derive benefits from the practices.

Conservation tillage is sufficient to restrict the growth and propagation space of weeds to achieve their suppression. In an experiment on the Loess Plateau of China, YangMei [39] found that no-tillage with stubble retention is an effective way to achieve weed control. Furthermore, conservation tillage can increase the population of predators of weed seed. R.H. Field [40] conducted a trial in western Hungary, and the results suggested that conservation tillage might attract seed-eating birds. N.F. Quinn [41] conducted a field experiment in Benton Harbor, Michigan, USA, and came to the conclusion that conservation tillage increases the number of predators of weed seeds, in particular spiders and ground beetles. No-tillage causes seeds accumulate on the surface and can reduce soil disturbance so there will be more predators, such as insects, rodents, and birds, and they could access seeds easier to increase the removal rates of weeds to realize weed control [42]. Moreover, using crop rotation along with conservation tillage is encouraged, as crop rotation can increase biodiversity to achieve weed control [43].

3.5. Conservation Tillage Can Stabilize and Increase Yield

A slight change in the climate will have a huge impact on food production and an adverse impact on crop yield. Conservation improves farming conditions from the aspect of hydrologic function, soil physicochemical properties, and the eco-environment, which stabilize and increase crop yield, enhance agriculture’s resistance to climate change, and maintain its core functions. Hongwen Li [44] collected data from the Conservation Tillage Research Center, Chinese Ministry of Agriculture, and analyzed four regions: the northeast ridge tillage areas, the north dryland areas (the Loess Plateau and North China along the Great Wall), the northwest China region, and the north China plain region. The results showed that conservation tillage has a positive effect on crop yield in China. Juan Li [21] conducted a test in Weinan City, Shaanxi Province. The results showed that crop yields had a significant improvement under conservation tillage. Rafiq Islam [24] made a similar finding in Carroll, OH, USA. With long-term no-tillage, crop yields are increased or at least maintained. This finding is not isolated. Yawen Huang [32] used meta-analysis to reveal that no-tillage is able to increase crop yields as well. The stable and increased crop yields ensure food security, provide raw materials for the industry, and help improve the economy. Thus, it is not hard to see that conservation tillage is able to help agriculture to maintain core functions.

4. Suggestions for the Application of Conservation Tillage in China

There is a large amount of arable land in China. According to the main data results of the third national land survey, there are 127,861.9 khm² of arable land in China. However, extensive agricultural production patterns, serious land degradation, agroecological vulnerability, and other problems are becoming more and more prominent under the threat of climate change. Conservation tillage is considered to have the potential to improve soil health, but conservation tillage is not widely used in China. Sourcing from the China Agricultural Machinery Industry Yearbook [45], the area under conservation tillage in China has shown a decreasing trend since 2015, with only 8162.03 khm², which is about 6% of arable land, under conservation tillage by 2019 (Figure 2). There is a vast territory in China, and its climate environment and cultivation patterns vary from region to region. Therefore, we divide the Chinese agricultural production area into four parts to discuss how to improve climate resilience through conservation tillage and propose some suggestions for prospective operability (Figure A1).

4.1. Northeast China

Northeast China, including Heilongjiang, Jilin, Liaoning, and the east part of Inner Mongolia, has always been recognized as a fertile land with a large area of black soil; it is one of the most important food production regions in China. For a long period of time, rotary tillage and residue removal or burning has caused serious land degradation in Northeast China [46]. As a consequence of climate change, extreme weather, including extreme precipitation, droughts, and wind storms, have exacerbated soil erosion, which brings a negative impact on the agricultural cultivation environment. Therefore, it is urgent to promote conservation tillage. According to field trials conducted by the Institute of Applied Ecology, Chinese Academy of Sciences, in Lishu, Siping, Jilin, China, conservation tillage is not only able to allow soil to hold more active organic matter and nutrients, but also to improve soil structure, enhance soil biological functions, and alleviate spring drought in Northeast China [46]. Shuxia Jia [47] conducted an experiment in Dehui County, Jilin Province, China. It was found that conservation tillage can reduce emissions of carbon dioxide and increase soil organic carbon concentration, soil microbial respiration, and soil microbial phospholipid fatty acids at a depth of 0–5 cm. When it comes to geographical environments, Northeast China is located at a high latitude, which results in a low atmospheric temperature. Low atmospheric temperature leads to low soil temperature, which is another critical factor limiting agricultural development in Northeast China. Yan Shen [48] discovered that soil temperature under no-tillage is lower than under moldboard plow and ridge tillage in an experiment conducted in Dehui city, Jilin Province, Northeast China. So, adopting strip-tillage might be a better alternative for clod areas to achieve the balance between soil temperature and mulching [46,49].

4.2. North China

North China is located in the middle and lower reaches of the Yellow River. Due to deep fertile soil and a long history of cultivation, the North China Plain is one of the most important food production areas in China. Winter wheat-summer maize is the main agricultural production mode in North China. Because of climate change, precipitation in North China has been affected, which has led to severe drought, plus the overexploitation of groundwater. The sustainable development of agriculture in North China is under threat [50,51,52]. Meanwhile, the long-term conventional tillage in North China has brought about a lot of problems, such as high energy consumption, serious soil compaction and degradation, environmental pollution, water waste, and increased production costs [53]. Francis Azumah Chimsah [54] used the PRISMA (preferred reporting items for systematic reviews and meta-analyses) approach and found that conservation tillage can improve the soil structure and increase soil nutrients. Besides improved soil health, there are a large number of studies confirming that conservation tillage has a positive impact on food production. Yin Minhua [55] took maize in northern China as a research object and using meta-analysis, found that no-tillage slightly increased the average yield by 3.1% compared with conventional tillage. It is clearly shown that the promotion of conservation tillage is significant for the sustainable development of agriculture in North China. Different tillage practices and mulching levels have different impacts on food production. To take full advantage of conservation tillage, the crop system has to be adapted to regional characteristics [56]. Liu Lijing [57] compared 10 kinds of tillage and crop residue management practices in terms of moisture content, soil bulk density, soil temperature, density of roots, crop yield, and water use efficiency and came up with the hypothesis that the most suitable conservation tillage patterns is corn-wheat no-tillage, with 100% cover and subsoiling for corn, and with no-tillage for wheat, both with 100% cover.

4.3. Northwest China

Northwest China is rich in solar and thermal resources and has a significant temperature difference between day and night, but it lacks water resources. Water scarcity is a major stumbling block to agriculture development in northwest China. Evaporation and drought have increased in northwest China as a result of climate change characterized by warming [58]. In order to increase the efficiency of conservation tillage, it is necessary to adapt different measures to the local conditions and focus on resolving the essential regional problems. Using meta-analysis, Lin Dong [59] evaluated the function of conservation tillage in managing climate change in Northwest China and drew the conclusion that conservation tillage can improve water-use efficiency, crop yield, and soil organic carbon. Addressing the problems of water resource limitation, coupling water-saving irrigation with conservation tillage in practical agronomic operations can be a good solution to reduce water usage and increase water use efficiency. Experiments conducted by Gansu Agricultural University in Lijiabu Village, Anding County, Dingxi, Gansu Province, in collaboration with the University of Adelaide and the NSW Department of Agriculture of Australia, show that no-tillage, with stubble retention, can significantly increase soil moisture at 0–10 cm on the Western Loess Plateau [60], which will assist in easing issues such as the area’s spring drought. Water-saving agriculture, according to Dr. Zou Xiaoxia’s research [61], can reduce irrigation water usage, enhance water use efficiency, increase food production, and even reduce carbon dioxide emissions. Experiments conducted by Hu Shunjun [62] in Xinhe County, Xinjiang Uygur Autonomous Region, revealed that water-saving irrigation can increase the water use efficiency of cotton. To solve the issue of water shortages and soil erosion in the northwest, conservation tillage integrated with soil and water conservation engineering measures, such as terraces, fish-scale pits, and check dams, confirmed to have better benefits for runoff retention and sediment reduction compared with independent micro-basin tillage [63].

4.4. South China

South China is affected by the monsoon climate, leading to abundant water resources. Since it is located at low latitudes, this also results in sufficient heat resources from the sun. Thus, South China is one of the major rice production regions in China. Due to abundant precipitation and frequent short-term heavy rainfall caused by climate change in the south, soil erosion and non-point source pollution are aggravated. At the same time, climate change-induced warming will create ideal environmental conditions for the spread of weeds and pest diseases. Conservation tillage is helpful to improve soil health while increasing food production. Xu Liuxing [64] discovered that no-tillage sowing promotes greater soil water, organic matter, and total nitrogen content in Guangzhou Province, China. Chen Zhongdu [65] investigated the soil structure on a farm with double-season paddy rice in Ningxiang County, Hunan Province, China, and detected that maintaining no tillage over time can enhance the formation of stable macroaggregates and produce better soil structure. The production of food will benefit from improved soil. After a comparative study with different tillage methods, Chengyan Zheng [66] noticed that crop yields under no-tillage in southern China were 3.4% higher than those under conventional tillage. Comparing no-tillage and plow-rotary tillage in a rice-wheat rotation in Jiangsu Province, China, Fujian Li [67] provided evidence that conservation tillage improved soil health and food production. Facing the problems of soil erosion in Southwest China, conservation tillage is able to use mulching to slow erosion. Barton, A.P. [68] conducted an experiment that showed that straw mulch is particularly effective in reducing erosion rates, after comparing the effectiveness of conventional tillage, no-tillage, straw mulch, polythene mulch, and intercropping on soil erosion. According to the hydrothermal condition in the South of China, conservation tillage can be used with cover crops in fallow time to improve the soil structure and minimize soil erosion. Moreover, conservation tillage paired with mixed agriculture can be taken into consideration for maximizing benefit. For instance, rice seedling-broadcasting with no-tillage, plus fish or duck cultivation in Guangxi, is a good example of both the economic and ecological benefits of using animals to reduce the usage of pesticide and chemical fertilizers, achieving a reduction in diffused pollution [69].

5. Discussions and Conclusions

Climate change impacts the cultivation environment through the change in temperature and precipitation, resulting in a decrease in agricultural production. Conservation tillage is beneficial for agriculture to improve resilience in response to climate change. Although we want to believe that conservation tillage is a perfect method, we cannot ignore the evidence suggesting that conservation tillage is not able to achieve our desired results and can bring some field management problems. For example, WangXiao-Bin [70] discussed the limitation of conservation tillage regarding weather conditions and soil type and found that conservation tillage can possibly reduce crop yield and only provide modest gains in improving soil health. B.D. Soane [71] reviewed some research in Europe and found that conservation tillage might lead to soil compaction, reduction in yield, and weed control problems. As for crop yield, conservation tillage generally shows better performance compared with conventional tillage. However, there are several cases indicating that conservation tillage decreased crop yield [72,73,74]. Cameron M. [72] collected data from publications, comparing both conventional tillage and no tillage practices, and observed that no-tillage had a negative impact on crop yield, rice (−7.5%) and maize (−7.6%) in particular. Through another meta-analysis of 74 publications, Stephen M. Ogle [74] found that no tillage can increase or decrease yields, depending on environmental conditions. Chris van Kessel [75] used a meta-analysis and concluded that conservation tillage can result in a highly significant reduction in yield for both humid and dry climates. The interesting finding is that there is some evidence confirming that conservation tillage is able to achieve yield increases in dry years and leads to yield reductions in wet years. For example, the field experiment conducted by Xiaobin Wang [76] in Shanxi Province (China) indicated that conservation tillage showed better grain yield performance in dry years and reduced grain yields in wet years. Shuang Liu’s [77] trials in Heilongjiang Province also had a similar result. In terms of greenhouse gases, we found that there is some evidence showing that conservation tillage can result in an increase in greenhouse gases. David Powlson [78] proposed that the evidence proving that conservation tillage can mitigate climate change is equivocal because a large part of the additional experimental evidence shows that the quantity of additional organic carbon in soil under no-tillage is relatively small; in large part, apparent increases result from an altered depth distribution. Dali Nayak [79] found that the belief that conservation tillage can reduce greenhouse gas is not a given by using meta-analysis. Peng Liu [80] performed a meta-analysis to evaluate the impact of crop straw retention on fields in China, and the results showed that the soil emission of CO₂, N₂O, and CH₄ were significantly increased under crop retention treatment by 23.64, 12.21, and 27.34%, respectively.

In order to achieve sustainable development of agriculture, many new trends are emerging in the world, which are often convergent with conservation tillage. For example, conservation tillage is one of the practices of regenerative agriculture, but regenerative agriculture includes not only the use of conservation tillage, but also crop rotation, cover crops, and holistic grazing to achieve sustainable agriculture development. We also advocate other practices paired with conservation tillage, based on unique local cultivation environments, to maximize the benefits of conservation tillage. For example, using cover crops to assist with controlling pest diseases is common in the context of climate change [37,81,82,83]. Lucie Büchi [83] conducted a long-term experiment in Switzerland, which illustrated that cover crops are essential to conservation tillage for weed management and soil nutrients. Using crop rotation, along with conservation tillage, is a win-win crop management option [84,85,86]. In Ethiopia, Worku Burayu [86] found that conservation tillage, combined with the use of cover crops, can offset the adverse effect of conservation tillage and improve soil health to increase yield. In terms of conservation tillage with mixed agriculture, Li [69] found rice seedling-broadcasting with no-tillage, plus fish or duck cultivation, provides more benefits. In Watkinsville, GA, USA, the research of Alan Franzluebbers [87] demonstrated the great advantages of conservation tillage combined with cattle grazing of cover crops. The above farming systems give a good example of how to choose the proper practice to be used along with conservation tillage.

Conservation tillage is beneficial for agriculture to improve resilience in response to climate change. No-tillage reduced the soil inversion and increased soil aggregate stability and decreased soil bulk density. Therefore, conservation tillage improved the soil structure, so that soil hydrologic function was improved. Moreover, there was more water infiltration, and the soil had more available water storage and higher water use efficiency with the residue, reducing evapotranspiration. Moreover, mulch slowed soil erosion and supplied the soil with organic matter and nutrients. Thus, conservation tillage provided a suitable living environment for soil organisms and farm animals. The diversity of field animals and mulching function together to achieve weed suppression and pest disease control. Better soil hydrologic function, better soil structure, better soil nutrient content, and better biodiversity all contributed to better soil health. As a result, crop yield was increased or at least maintained. As for greenhouse gases, no soil disturbance and residue incorporation led to greenhouse gas fixation and carbon sequestration. In conclusion, conservation tillage functions to enhance climate resilience in agriculture by improving soil health to stabilize crop yield and mitigate climate change by reducing greenhouse gases. As the climate challenges faced by agriculture become more and more severe, China should develop conservation tillage, in accordance with local conditions. We reviewed how conservation tillage improves climate resilience and provided suggestions to support the promotion of conservation tillage. In the future, conservation tillage can be better implemented to achieve climate resilience under different conditions across China.