Unlocking the Benefits of Carbon Sequestration for Enhancing Soil Health

This abstract investigates the profound interconnection between carbon sequestration methods and soil health enhancement, crucial for sustainable land management. Evaluating various strategies, including cover cropping, reduced tillage, agroforestry, and biochar application, this study elucidates their role in augmenting soil organic carbon levels and fostering microbial diversity, thereby improving soil structure, water retention, nutrient cycling, and overall fertility. It examines the reciprocal impacts of carbon sequestration and soil health on agricultural yields, ecosystem resilience, and climate change mitigation. Furthermore, the research outlines barriers to widespread adoption, such as economic constraints and policy frameworks, emphasizing the need for interdisciplinary approaches and technological innovations. Overall, this study advocates integrating carbon sequestration practices into agricultural techniques as a pivotal step towards mitigating climate change and fortifying soil health for sustainable land use and resilient ecosystems.

Soil Quality: A Critical Review

From plot to national scales, sampling, analysis, and visual inspection of soil are common methods used to evaluate its condition and potential for use. However, due to the complexity and site-specificity of soils, the legacy impacts of past land use, and trade-offs across ecosystem services, selecting relevant soil parameters and interpreting measurements are not simple tasks. Here, we go over the definition, methods of assessment, and choices and interpretations of indicators for soil quality and related concepts. Assessing soil condition and potential usage involves a range of methods, from small-scale sampling to nationwide analyses. Despite their prevalence, these approaches face challenges due to the intricate nature of soils, their site-specific characteristics, historical land use impacts, and the need to balance various ecosystem services. Selecting pertinent soil parameters and interpreting measurements becomes a complex task. In this context, we delve into the definition, assessment methods, and the choices and interpretations of indicators related to soil quality. Our focus is on widely used indicators within agricultural land use. Notably, explicit evaluations of soil quality for specific risks, functions, and ecosystem services remain limited. Furthermore, there is a scarcity of systems providing clear frameworks for interpreting measured indicator values, hampering their acceptance by both policymakers and land managers. We explore innovative indicators that shed light on often overlooked soil properties and processes. Biological/biochemical indicators are under-represented but show great potential. Soil quality assessment should specify targeted soil threats, functions and ecosystem services. Increasingly interactive assessment tools must be developed with target users.

Impact of Cropping Systems on Soil Organic Carbon Levels and Enzyme Activity

Monocropping makes agriculture more susceptible to the adverse effects of climate change. Resilient agriculture systems that can buffer crops against various agricultural vulnerabilities is the need of the hour. In this context, a study was conducted to assess the impact of various rice based cropping systems on soil health.Aims: To study the effect of different rice based cropping systems on soil enzyme activity and organic carbon.Study Design: Randomized block design, Replications – 3.Place and Duration of Study: Integrated Farming System Research Station (IFSRS) of Kerala Agricultural University located at Karamana, Thiruvananthapuram, during kharif, rabi and summer seasons of 2019-2020.Methodology: The experiment consists of eleven cropping systems (T1 : rice - fallow - fallow, T2 : rice - rice - fallow, T3 : rice - daincha - cowpea, T4 : (rice + daincha) - rice - green gram, T5 : rice - cassava - amaranthus, T6 : rice - cassava - cowpea, T7 : rice - para grass - fodder cowpea, T8 : rice - fodder cowpea - fodder maize, T9 : rice - okra - culinary melon, T10 : rice - okra - yard long bean and T11 : rice - rice – amaranthus).Results: Soil organic carbon and enzyme activities were found highest in the cropping system (rice+daincha) – rice – green gram during kharif. During rabi, soil organic carbon and activity of urease and acid phosphatase were highest in rice- daincha- cowpea while dehydrogenase activity was highest in rice- fodder cowpea – fodder maize. During summer, rice- okra – yard long bean, rice- cassava- amaranthus and rice- cassava – cowpea recorded the highest urease, acid phosphatase and dehydrogenase activity, respectively. The organic carbon was highest for the sequence rice – okra –culinary melon. The soil organic carbon and enzyme activities were least in rice- fallow-fallow cropping sequence during all the three cropping seasons.Conclusion: Brown manuring, use of leguminous crops and cover crops in the crop sequence instead of leaving the land fallow and addition of organic sources of nutrition increase the soil organic carbon and enzymatic activity of microbes. The increase in soil organic carbon and activity of enzymes in soil owing to crop rotation of rice with arable crops relies on the crop species which are cultivated.

Conservation Agriculture System Impact on Soil Nutrient Status in Eastern Dry Zone of Karnataka, India

Tillage is the physical manipulation of soil into optimum conditions, which enhance the soil health for better crop productivity. A field investigation was carried out to evaluate conservation agriculture effect on soil nutrient conservation and set up in spilt plot design. Zero tillage (M3) witnessed significantly (P<0.05) greater nitrogen availability (288.17, 251.39 and 239.70 kg ha-1), K2O (229.04, 209.80 and 193.73 kg ha-1) than conventional tillage (M1) at soil depths 0-7.5, 7.5-15 and 15-30 cm, respectively. In green manuring practices, horse gram (C3) recorded OC (0.53, 0.51 and 0.47 %), available sulphur (23.38, 20.61 and 18.10 mg kg-1) followed by sun hemp. The interaction combination of M3C3 recorded highest soil nutrient status. Significantly lowest microbial population were found in M1, was due to faster decomposition organic matter resulted in unfavourable condition for survival. Overall adopting M1 alone (1 Ploughing + 2 harrowing + 1 intercultural operation) adversely affect soil health.

Integrated Nutrients Management for Future Production: A Review

As per the estimate by the United Nations, the world population will increase to 11 billion, by 2050. This rapid increase in the population is of global concern, creating responsibilities on the shoulders of the scientists to fetch the rapidly increasing population along with the problem of reduced land holding, sudden climatic challenges, and imbalanced nutrition coupled with deficiencies of nutrients. It is necessary to continuously review and modify agricultural practices and technologies in order to meet human demands while respecting the ecological boundaries of our planet. Among these technologies application of fertilizers has been crucial for raising crop yield, agricultural productivity and food security. However, the application of fertilizer has an environmental cost and they haven't been a very productive factor in helping many poor farmers to escape poverty economically, especially in the areas where the fertilizer application has an imbalance and inappropriate fertilizer has been applied on the lower fertile soils which have little or no desirable effect on the crop yield. The efficient use of fertilizers can be increased by using agronomic practices to apply existing mineral fertilizers, which generally contain N, P, and K, at the proper time, place, amount, and composition. However, the overall progress made to minimize the negative consequences is insufficient to bring about the necessary change toward sustainable agriculture in underdeveloped nations. Farmers must integrate the management of nutrients and soil fertility into their farming practices in order to meet the increasing population's demand for food. This paper reviews the concepts of integrated nutrient management in the context of its eco-friendly nature and sustainability.

Biochar: A Comprehensive Overview of Its Role in Soil Health

Soil health plays a crucial role in agricultural productivity, environmental sustainability, and global food security. In recent years, biochar has emerged as a promising soil amendment due to its ability to enhance soil fertility, nutrient retention, water holding capacity, and overall soil health. From an agricultural standpoint, using biochar as a soil conditioner has various advantages, including improved physical, chemical, and biological qualities of soils, which leads to enhanced crop output. Biochar can be utilised for soil carbon sequestration, reducing the bioavailability of pollutants impacting living organisms, and water treatment due to its physicochemical qualities This review paper aims to provide an in-depth analysis of the role of biochar in improving soil health.

Response of Different Levels of NPK and Zinc on Soil Health in Black Gram (Vigna mungo L.)

An experiment was conducted during in Zaid season (March 2022-June 2022) to study the “effect of different levels of NPK and Zinc on soil health in black gram (Vigna mungo L.)” on central research farm of Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj. A randomized block design was used to set up the experiment, with three levels of NPK (0%, 50%, and 100% NPK) and three levels of zinc (0%, 50%, and 100% zinc). The outcome demonstrates that inorganic fertilizer application had a non-significant effect on soil physical-chemical parameters (BD, PD, pH, EC and OC) and significant increase in pore space, water holding capacity, available nitrogen, phosphorus, potassium and zinc in treatment T9 [NPK at 100% + zinc at 100%] than other treatments.

Influence of Sagarika-Liquid with Inorganic Fertilizers for Enchaning the Soil Health and Yield of Green Gram (Vigna radiata L.)

An experiment was conducted on sagarika-liquid with inorganic fertilizers during Zaid season 2022 at the central research farm of Department of Soil science and Agricultural chemistry, to enhance the productivity. The design applied was 3x3 RBD having three levels of Sagarika-liquid @2ml, 3ml and 4ml L-1 and N P K @ 50, 75and 100%. The result obtained with treatment T9[N P K @100%+ 2 Spray of Sagarika 4ml l-1] that showed vermicompost in combination resulted in a slight change in soil pH at 0-15 cm and 15-30 cm were found 7.12 and 7.27and EC 0.35 and 0.32 dS m-1 respectively. The significant results were in pore space 47.90 and 45.52%, water holding capacity 46.10 and 43.60%, organic carbon 0.54%, 0.44%, and available nitrogen, phosphorus and potassium was found to be significant among other treatments in Green gram cultivation and soil quality improvement. The maximum yield regarding, gave the best results with respect to plant height 45.34 cm, number of pod plant-1 28.16, and number of seed pod-1 8.45. It gave highest yield 1.96 t ha-1. It was also revealed that the application with organic manures was excellent source for fertilization than fertilizers.

Biofertilizers and Inorganic Fertilizers Application Impact on Available Nutrients in Soil of Kharif Maize

A field experiment entitled “Biofertilizers and inorganic fertilizers application impact on available nutrients in soil of kharif maize” was conducted at Agriculture College Farm, Bapatla, during kharif of 2020-21. The experiment was laid out in randomized block design (RBD) with seven treatments and replicated thrice. The treatments consisted of T1- Control; T2- 100% RDF; T3- 125% RDF; T4 – 100% RDF +Vesicular Arbuscular Mycorrhizae (VAM); T5- 100% RDF +VAM + Azospirillum + Phosphate Solubilizing Bacteria (PSB); T6- 75 % RDF + VAM; T7- 75 % RDF + VAM + Azospirillum + PSB. We recorded the available macro nutrients (nitrogen, phosphorus and potassium) and micronutrients (zinc, iron, manganese and copper) of maize during the study. The results revealed that available nitrogen during kharif of 2020-21 was significantly (P < 0.05) higher with 125 % RDF (T3) that was on par with T5 (100% RDF + VAM + Azospirillum + PSB) and T4 (100% RDF + VAM). Higher available phosphorus and potassium were recorded in the treatment T5 and it was on par with T7, T3 and T4 at knee high, tasseling and harvest stage of maize. However, micronutrient status was higher with application of 100% RDF +VAM + Azospirillum + PSB but non-significant at all the growth stages of maize during both the years of study. The biofertilizers have to be applied side-by-side with inorganic fertilizers to improve nutrient availability and increased the fertility status of soil and productivity.

Oil palm intercropping system: A potential nature-based solution to improve soil biology activities in North Sumatra plantation, Indonesia

Aims@#Intercropping system in oil palm plantation is recognized as one of a nature-based solution as well as a promising sustainable practice. This study aimed to observe the advantages of existing intercropping system in one of North Sumatra’s oil palm plantation. It is achieved by analyzing the population of soil bacteria and fungi in oil palm intercropping fields with sorghum and cassava, compared with the non-intercropping field that using Mucuna bracteata (MB) as a common legume cover crop in oil palm plantations.@*Methodology and results@#Soil samples were collected from the weeded circle and windrow area (the area between palms within the row). The results showed that the highest and the lowest soil bacteria populations were in sorghum (1.7 ± 1.4 × 108 CFU/g) and MB (1.7 ± 0.4 × 107 CFU/g), while the highest and the lowest soil fungi populations were in sorghum (4.3 ± 2.9 × 106 CFU/g) and cassava (2.1 ± 0.8 × 106 CFU/g).@*Conclusion, significance and impact of study@#The intercropping system in this study showed a significant difference in the bacteria population, while the fungi population had no difference compared to the non-intercropping system. The bacterial and fungi population results also indicate that the intercropping system potentially enhances the soil's biological activity as an indicator of improved soil health. It is also followed by a slightly higher soil organic carbon value in intercropping system. This research suggests that further studies should be done to identify specific soil functional microbes (nutrients fixers and solubilizers). The future research will be used as a reference for promising biofertilizer agents in supporting sustainable crop production.

Response of Conservation Agriculture on System Productivity and Carbon Sequestration in Rice-Based Cropping Systems

Low crop yields due to constant monocropping systems and deteriorating soil health in a smallholder farmers’ field of Indo-Gangetic plains of India have led to a quest for sustainable production practices with greater resource use efficiencies. The aim of the study was to elucidate the short term effects of conservation agricultural systems on productivity, soil health and carbon sequestration rate of soils in three different diversified cropping systems. The treatments consisted of two different tillage systems (conventional and reduced tillage), two mulch levels (no and straw mulch) and two levels of fertility (100 and 75% RDF) were compared in three rice-based cropping systems (rice-wheat; rice-vegetable pea-greengram; and rice-potato-maize sequences) for two years on an experimental field (clay loam) located at Norman E Borlaug Crop Research Center, Pantnagar, India. The resource conservation technologies (RCT) i.e. reduced tillage, mulch, and 100% RDF had recorded 2.5 and 3.0% higher system productivity and relative production efficiency in rice-vegetablepea-greengram and rice-potato-maize sequences, respectively in two consecutive years. Conservation tillage had sequestered three times higher carbon than conventional tillage while mulching acted four times higher than non-mulched condition in agricultural soils. Even though cropping system not significant significantly influenced on carbon sequestration, rice-vegetablepea-greengram sequence had recorded higher carbon sequestration rate and higher soil organic carbon stock noted in surface plough sole layer than any other cropping systems. Therefore, our results suggested that Indo-Gangetic farmers should consider adopting resource conservation practices together in indogangetic area because of benefits to soil health, carbon sequestration and system productivity.

Productivity and profitability assessment of organically grown vegetables embedded in rice based cropping sequences in Sikkim Himalayas, North East India

Aim: The objective of the present study was to identify economically viable, profitable and resource efficient vegetables embedded rice-based cropping sequences under organic management for marginal and small farmers of Sikkim Himalayas, India.Methodology: Three-year fixed plot study was conducted to evaluate seven rice–based cropping sequences viz., rice–fallow (farmers’ practice), rice–fenugreek (leafy vegetable), rice–coriander (leaves), rice–radish, rice–broccoli, rice–potato and rice–vegetable pea were replicated four-times in a completely randomized block design. Results: Among the various rice – based cropping sequences, cultivation of rice–coriander (leaves) recorded higher production (67.3 kg ha-1 day-1), system productivity (24.6 t ha-1), relative economic efficiency (1040%) and net returns (376.1x103). However, rice-broccoli and rice–vegetable pea sequences recorded 8.6 and 4.4% higher B: C ratio, respectively, over the rice–coriander system. With regards to soil health, rice – vegetable pea cropping sequences resulted in maximum improvement in soil organic carbon (SOC) (1.26%), available soil N (415.2 kg ha-1), P (22.8 kg ha-1) and K (411.5 kg ha-1), soil microbial biomass carbon (SMBC) (344.7 µg MBC g-1 soil), dehydrogenase activity (DHA) (24.0 µg TPFg-1 soil h-1) and fluorescin di acetate (FDA) (38.8 µg FDAg-1 soil h-1) among the cropping sequences. Interpretation: Induction of vegetables in rice–fallow system under assured irrigation condition of Sikkim Himalayas, India not only enhances the farm productivity and profitability but also sustain the soil health on long term basis. Thus, rice-vegetable pea/coriander/broccoli based production systems under organic management hold great promises for sustaining livelihood of organic growers in Sikkim Himalayas over conventional rice– fallow system.

Plant and Soil Biota: Crucial for Mitigating Climate Change in Forests.

Interest in forestation is rising with increasing recognition that global changes can negatively affect plant diversity and ecosystem function. It is known that forests influence climate through physical, chemical, and biological processes and ecohydrology need substantially more research. Functional interactions among vegetation, soils, and hydrologic processes permit the trees to maintain their symbioses in the soil. However, global change affects forests and soil health, influencing the population, diversity and activities of soil microbes, including symbiotic fungal populations. Although plants are sessile organisms, selected agroforestry tree species (mycorrhizal dependent plants) can be employed in forestation to encompass environmental stresses increased by global changes. This review was done to explore current information on forest for mitigating climate change, with respect to the research results on soil microbiota and its hydrologic impacts. Thus, relevant findings related to the benefits of soil health are emphasized. Accordingly, I discuss interdisciplinary knowledge required to understand the potential of forest to mitigate climate change.

Soil Quality Changes and Quality Status: A Case Study of the Subtropical China Region Ultisol.

Aims: To provide a soil quality assessment frame work and threshold limits for assessing soil quality in Ultisol of subtropical China region. Study Design: Selected minimum data set for soil quality assessment and threshold limits for the study were total carbon, nitrogen, soil pH and phosphorus, biomass carbon, nitrogen and phosphorus, maize grain and fresh potato tuber yields. Soil data (2000-2010), maize grain and fresh potato yield data (2000-2009) from a long term experiment under the Institute of subtropical Agriculture, China were analyzed using the SAS statistical package and means were graphically compared to determine threshold limits for selected data set and fitted into a soil quality model. Place and Duration of Study: The key Laboratory for Agro-ecological Processes in Subtropical Regions, Chinese Academy of Sciences; Institute of Subtropical Agriculture, Changsha, Hunan China long-term experimental site in Taoyuan county, conducted from the year 2000 to 2010. Methodology: Soils samples at the experimental fields were obtained from depths 0-20 cm using an auger at each replicate in triplicates and homogenized to obtain a composite sub sample, air-dried, sieved through 2.0 mm to obtain samples for analysis in the Laboratory. Parameters analyzed for were organic carbon concentration, measured by the combustion method using an automated C/N analyzer (Vario MAX CN, Elemental Co., Germany) while total nitrogen was by the Kjeldahl method of ISSCAS (1978). Microbial carbon, nitrogen and phosphorus levels were determined using the chloroform-fumigationextraction method (Jenkinson and Powlson, 1976; Vance et al., 1987; Brookes et al., 1982) and adopting the conversion factors 0.45 (Wu et al., 1990), 0.45 (Brookes et al., 1985), and 0.29 (Wu et al., 2000) respectively for the C, N and P. Extractable N and Olson P were taken from values obtained from the non fumigated soil samples. Data obtained were statistically analyzed using the SAS package for ANOVA and significant means were separated using the Duncan’s New Multiple Range Test (DNMRT). Treatment means were also matched graphically to delineate critical threshold limits between classes for each parameter. Soil quality was assessed by using the Parr et al. (1992) equation; SQ =ƒ(SP,P,E,H, ER,BD,FQ, MI); where SQ= soil quality, SP= soil properties, P = potential productivity, E=environmental factor, H= health (human/animal), ER= erodibility, BD= biodiversity, FQ= food quality and MI= management input. A score scale of 1 to 5 was used in the assessment of parameters in the model; where 1 is best and 5 is the worst condition. However, E, H, ER, FQ and MI were each scored 1.0 because the long-term experiment has an environmental component, health factor, biodiversity, food quality and management input components that are being optimally managed. Therefore SQ= f(SP, P) was used to assess quality of the Ultisol at the uplands and slope land locations. Results: At the uplands, the practice of maize-rape/marsh residue+NK (8.54gkg-1 C, 1.0 gkg-1 N and 5.67 mgkg-1 P) treatments could be rotated with Maize-rape/nil fertilizer (7.51 gkg-1 C, 0.87 gkg-1 and 0.39 mgkg-1 P) to encourage improved soil quality by allowing for more years with soil carbon sequestration, nitrogen and phosphorus credit than years of depletion and discourage soil degradation. At the slope lands, treatments that combined application of organic and inorganic fertilizer materials [Sweet potato-rape/NP+straw (7.18 gkg-1 C, 0.88 gkg-1 N and 0.38 mgkg-1 P) and Peanut-broadbean/NP+straw (6.81 gkg-1 C, 0.86 gkg-1 N and 0.38 mgkg-1 P)] improved soil quality significantly over time by sequestering significantly higher total carbon, nitrogen and phosphorus better than sole inorganic fertilizer [Sweet potato-rape/NPK (6.52 gkg-1 C, 0.81 gkg-1 N and 0.38 mgkg-1 P)]. Conclusion: Ultisol at the upland positions had better quality (SQ1) than those at the slope (SQ2) positions. Threshold limits for nutrients, pH and yield of maize and Fresh Potato tubers in the subtropical China region Ultisol was developed.