Returning straw to the field is the most significant straw utilization technique for China’s green development. It can provide nutrients for crop growth and improve soil organic matter content. However, there are no standard parameters for measuring the nutrient content of straw directly returned to the field. In addition, the nutrient content of straw in the field is disregarded and the least researched. Therefore, to address these issues, the current research examines the main nutrient composition of straw returned directly to fields and the potential substitution of straw for chemical fertilizers. This study used the latest data on the crop straw-to-grain ratio and straw’s direct return to the field from the Database of Agricultural Crops Straws Resources in China (DACSRC) as the basis for a detailed estimation of the amount of crop straw nutrient resources and straw’s direct return to the field. The straw nutrient resources were measured based on straw yield and the nitrogen (N), phosphorous (P₂O₅), and potassium (K₂O) contents. The results reveal that the maximum amount of straw returned directly to the fields in China was 517 teragram (Tg), while 128 Tg (25%) of the total was not collected but left on the field. The North China region had an enormous amount of direct straw return at 176 Tg (34%), while South China had the least amount at 26 Tg (5%). The amounts of seasonally available N, P₂O₅, and K₂O from straw directly returned to fields are 2 Tg, 1 Tg, and 7 Tg, respectively. In addition, the amount of available straw nutrient resources returned to the field per hectare (ha) was 78 kg. The quantity of straw-originating seasonally available nutrients corresponds to 23% of the chemical fertilizers applied, which can substitute 10% N, 9% P₂O₅, and 58% K₂O. The study provides critical insights on effective ways to improve straw fertilization through an increased rate of straw returned directly to fields and releasing seasonal nutrients.

Enormous quantities of straw in China are burnt in open fields or discarded randomly, leading to a serious waste of biomass resources and environmental pollution. To accelerate sustainable development, straw resources must be used efficiently and reduce carbon emissions. Based on a systematic literature review, this study summarizes China’s latest development in straw utilization. It analyzes the accounting methods, carbon emission reduction effects and potential of straw utilization. The study highlights that straw utilization in China can be categorized into five-dimensional straw utilization models (FDSUM). The cost of collection, storage and transportation, and straw utilization technology are the main factors affecting straw utilization. FDSUM contributes greatly to agricultural carbon reduction. Straw-to-fertilizer has the highest contribution, and straw-to-fuel has the largest carbon emission reduction potential. The carbon emission reduction from straw–to-fuel utilization in 2020 was 63.43 × 10⁹ kg CO₂. In addition, China has not developed a standardized carbon accounting method for straw utilization. China needs to prioritize straw-to-fertilizer and straw-to-fuel conversion and develop low-carbon production technologies. This study will serve as a reference to further improve the utilization of straw in China and provide preliminary ideas for establishing a unified national carbon accounting system for straw utilization.

Agricultural sensors are essential technologies for smart agriculture, which can transform non-electrical physical quantities such as environmental factors. The ecological elements inside and outside of plants and animals are converted into electrical signals for control system recognition, providing a basis for decision-making in smart agriculture. With the rapid development of smart agriculture in China, agricultural sensors have ushered in opportunities and challenges. Based on a literature review and data statistics, this paper analyzes the market prospects and market scale of agricultural sensors in China from four perspectives: field farming, facility farming, livestock and poultry farming and aquaculture. The study further predicts the demand for agricultural sensors in 2025 and 2035. The results reveal that China’s sensor market has a good development prospect. However, the paper garnered the key challenges of China’s agricultural sensor industry, including a weak technical foundation, poor enterprise research capacity, high importation of sensors and a lack of financial support. Given this, the agricultural sensor market should be comprehensively distributed in terms of policy, funding, expertise and innovative technology. In addition, this paper highlighted integrating the future development direction of China’s agricultural sensor technology with new technologies and China’s agricultural development needs.

Renewable energy is predicted to play a crucial role in the energy sector as transitioning from fossil fuels to biofuels is key to achieving carbon neutrality. The comprehensive utilization of livestock manure and crop residues as a viable source of biofuels can play a significant role in Ghana’s future energy system. This current study aims to examine and predict the biofuel potential in Ghana from animal manure and crop residues. The biogas-biomethane potential of animal manure is determined using anaerobic digestion technology, whereas crop residues’ bioethanol potential is assessed using computational and analytical approaches. The findings demonstrate that animal manure biogas potential is 237.72 normal million cubic meters (NMm³). The highest manure-biogas potential per animal is from cattle (27.15 Nm³) and pigs (18.15 Nm³), while the least contribution is from chickens (1.80 Nm³). In addition, the annual bioethanol production is 3.74 gigaliters (GL), and residues from maize (0.88 GL), yams (0.82 GL), and plantains (0.47 GL) had the largest share per annum. By 2100, Ghana has the potential to produce 1288.56 NMm³ of manure-based biogas which can offset 13.88% of liquefied petroleum gas (LPG) consumption. The biogas potential positively correlates with the biomethane potential of 901.99 NMm³. Furthermore, 91.85% of the 14.76 GL of bioethanol will be from food crop residues. This study provides critical information to lawmakers and energy planners with strategies to achieve energy security and minimize the ecological footprint in an optimistic scenario.

Reducing the use of nitrogen fertilizers and returning straw to field are being promoted in northeast China (NEC). In this paper, the agricultural production system model (APSIM) was applied to assess the long-term variations of crop yield and soil GHG emissions in a maize mono-cropping system of NEC, and the simulation results were combined with lifecycle assessment to estimate annual GHG emissions (GHG_L) and GHG emission intensity (GHG_I, GHG emissions per unit yield) of different agricultural practices. Under current farmers’ practice, emissions due to machinery input (including production, transportation, repair, and maintenance) and soil organic carbon (SOC) decline accounted for 15% of GHG_L, while emissions from nitrogen fertilizer input (production and transportation) and direct N₂O emissions from soil accounted for the majority (~60% of GHG_L). Current farmers’ practice in terms of N application and residue management are nearly optimal for crop production but not for climate change mitigation. Reducing N input by 13% and increasing straw retention by 20% can maintain crop yield and SOC, and also reduce GHG_L and GHG_I by 13% and 11%, respectively. However, it is not feasible to incorporate the straw used as household fuel into soil, which could incur substantial fossil CO₂ emissions of 3.98 Mg CO₂-eq ha⁻¹ resulting from the substitution of coal for straw. APSIM was successful in simulating crop yield, N₂O emissions, and SOC change in NEC, and our results highlight opportunities to further optimize management strategies (especially for the nitrogen and straw management) to reduce GHG emissions while maintaining crop yield.

Anthropogenic global warming and the depletion of nonrenewable resources necessitate a transition towards bioenergy to accelerate sustainable development and carbon neutrality. This study quantified the availability and energy potential of crop (cereals, legumes, roots and tubers) straws based on data from the Northern, North East and Savannah regions in Ghana. The annual technical straw potential was 2,967,933 tonnes, whilst the crop straws with the highest technical potential were yam (935,927 tonnes), groundnut (485,236 tonnes), maize (438,926 tonnes) and soybean (374,564 tonnes). The technical energy potential of all the crop straws was 42,256 TJ, although the energy potential of yam, groundnut, maize and soybean was 13,922 TJ, 7611 TJ, 5704 TJ and 5409 TJ, respectively. There was a linear correlation between the straw produced and the energy potential per region. The Northern region (28,153 TJ) recorded the highest energy potential followed by the Savannah (8330 TJ) and North East (5773 TJ) regions. To serve as context, the research placed an emphasis on the sustainability of crop straws for bioenergy and added a brief analysis of the life cycle assessment (LCA) of bioenergy scenarios to explore the environmental sustainability of crop straw-based power generation. This study will serve as a reference in understanding LCA inference on practicable research of crop straw-based, power plant expansion in Ghana and Sub-Saharan Africa (SSA).