The agricultural sector is the most important economic component in Afghanistan, as 80% of the population is involved. The improvement of cereal production is an urgent task to meet the nation’s demand for the staple within the limited arable land. To promote a sustainable crop production system, this study examined the soil quality to learn the basic knowledge of soil fertility and the environmental impact of different rice–wheat cropping systems in Khost, Afghanistan by using the life cycle assessment (LCA) method. The economic analysis of each farming system was conducted by the data gathered by the farmers’ interviews along with LCA data collection. The analysis considered the on-farm activities, which were required to produce 1 kg of wheat and rice. It included energy use, production, and farming inputs such as fertilizer and agrochemicals. Conventional farming with organic fertilizer application (CF+OF) was compared with conventional farming (CF). The LCA results showed the total greenhouse gas (GHG) emission was higher in rice production compared to wheat production. However, CO2 absorption by the crops was far greater than the total GHG emission in both systems and showed great potential for soil carbon sequestration for mitigation of global warming. The soil examination revealed the CF+OF system increased soil total carbon (TC), active C (AC), total N (TN), soil organic carbon storage (SCS), P, and K+ after four years of organic fertilizer application. The yield of each crop was slightly higher in the CF system; however, the CF+OF system increased net income by reducing the cost for fertilizer. The study concluded the CF+OF system can improve soil fertility in the long term while saving the farming operation cost. Further research is required to determine the best combination of practices to improve cattle manure characteristics and farm management for soil carbon sequestration to promote a sustainable farming system in the country.

Agricultural fields can store substantial amounts of atmospheric carbon in the soil. In 2011, the Environmentally Friendly Farming Direct Payment Program (EFFDPP) began as a way to promote sustainable agriculture, but the approved methods for receiving the subsidy are limited to the use of manure and cover crops. For evaluating other options for the EFFDPP, we calculated soil carbon inputs and CO 2 emissions in four nature farming (NF) systems for comparisons with conventional farming (CF) and environmentally friendly farming (EF) systems. In 2015, we collected data on farm management from interviews and conducted a field experiment for NF. According to the calculations using a modified Roth C model, the ability for soil carbon sequestration predicted over the next 20 years is the highest in a no-till NF system with grass mulching. CO 2 emission per ha for CF was 4.8 t CO 2 /ha, which was eight times higher than that for NF. However, the highest CO 2 emission per kg of crop was noted in NF with no grass mulching due to very low yield. The total CO 2 emission for CF was similar to that for EF. The NF systems were beneficial in reducing CO 2 emission, but a combination of other approaches is required for satisfying EFFDPP criteria.

Nature farming is a farming system that entails cultivating crops without using chemical fertilizers and pesticides. The present study investigated the bacterial and fungal communities in the rhizosphere of soybean grown in conventional and nature farming soils using wild-type and non-nodulating mutant soybean. The effect of soil fumigant was also analyzed to reveal its perturbation of microbial communities and subsequent effects on the growth of soybean. Overall, the wild-type soybean exhibited a better growth index compared to mutant soybean and especially in nature farming. Nodulation and arbuscular mycorrhiza (AM) fungi colonization were higher in plants under nature farming than in conventionally managed soil; however, fumigation drastically affected these symbioses with greater impacts on plants in nature farming soil. The rhizosphere microbiome diversity in nature farming was higher than that in conventional farming for both cultivars. However, the diversity was significantly decreased after fumigation treatment with a greater impact on nature farming. Principal coordinate analysis revealed that nature farming and conventional farming soil harbored distinct microbial communities and that soil fumigation significantly altered the communities in nature farming soils but not in conventional farming soils. Intriguingly, some beneficial microbial taxa related to plant growth and health, including Rhizobium, Streptomyces, and Burkholderia, were found as distinct microbes in the nature farming soil but were selectively bleached by fumigant treatment. Network analysis revealed a highly complex microbial network with high taxa connectivity observed under nature farming soil than in conventional soil; however, fumigation strongly broke it. Overall, the results highlighted that nature farming embraced higher microbial diversity and the abundance of beneficial soil microbes with a complex and interconnected network structure, and also demonstrated the underlying resilience of the microbial community to environmental perturbations, which is critical under nature farming where chemical fertilizers and pesticides are not applied.

To understand the distribution of the cultivable fungal community in plant tissues from nature farming tomato plants, we sampled plants of seven different tomato cultivars and recovered 1742 fungal isolates from 1895 stem tissues sampled from three sites in Japan. Overall, the isolation frequency was low (3–13%) and the isolation and colonization frequencies did not vary significantly as a function of the cultivar. The fungi were divided into 29 unique operational taxonomic units (OTUs) with 97% ITS gene sequence identity, the majority of which belong to Ascomycota (99.3%). The dominant genera of cultivable endophytic fungi were Fusarium (45.1%), Alternaria (12.8%), Gibberella (12.0%), and Dipodascus (6.8%). The alpha diversity of the fungal endophytes varied among tomato cultivars. Ordination analysis performed to investigate patterns of endophyte community assemblages on the various cultivars revealed that host cultivars had a significant impact on the endophyte community assemblages in all the study sites. Some of the taxa Fusarium, Alternaria, and Penicillium were found on all cultivars, while few were uniquely present in different cultivars. The dominant taxa may be adapted to the particular microecological and physiological conditions present in tomato stems.

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