Effects Of Different Organic Amendments Research Articles

Effect of different organic amendments and fertigation on growth, yield, quality of watermelon (Citrullus lanatus Thunb.) and soil properties of Theri land (Red sand dune) of southern Tamil Nadu

Effect of different organic amendments and fertigation on growth, yield, quality of watermelon (Citrullus lanatus Thunb.) and soil properties of Theri land (Red sand dune) of southern Tamil Nadu

Effect of different organic amendments on phosphorus dynamics of blackgram (Vigna mungo)

Legumes play a significant role in sustainable agriculture through their ability to improve soil fertility and health. With a mutual symbiotic relationship with some bacteria in soil, they can improve nitrogen (N) amount through biological N-fixation (BNF). But to maximize such functions, legumes need more phosphorus (P) as it is required for energy transformation in nodules. Besides, P also plays a significant role in root development, nutrient uptake and growth of legume crops. A field experiment was conducted during rainy (kharif) season of 2019 at IFS unit, College of Agriculture, (University of Agricultural Sciences, Dharwad), Vijayapur, Karnataka to study the effect of different combination of organic sources on phosphorus dynamics of blackgram [Vigna mungo (L.) Hepper]. Among different treatments, the application of vermicompost + ghanajeevamrutha @ 100% RDP + Rhizobium + PSB recorded significantly higher soil available phosphorus (36.30 kg/ha) and uptake by blackgram (16.08 kg/ha). This study has demonstrated the dynamics of phosphorus through different organic sources in blackgram.

Comparison of the Effects of Different Organic Amendments on the Immobilization and Phytoavailability of Lead

Organic materials, such as straw, animal manure, and their processed product biochar, are known to exhibit agronomic effects and the ability to remediate heavy metal contamination. However, knowledge regarding the relative effects of different organic amendments in soils on heavy metal immobilization and phytoavailability remain limited. Consequently, the effects of maize straw (MS), chicken manure (CM), mushroom cultivation waste (MW), and sawdust biochar (SB) on the immobilization and phytoavailability of lead (Pb) in wheat plants were investigated in this study using pot experiments. The results showed that the artificial application of Pb reduced soil pH, while increasing the total organic carbon (TOC) and cation exchange capacity (CEC) to various extents. Furthermore, the Pb treatment increased the adsorption of Pb by wheat grains (0.83 mg∙kg−1), resulting in decreased above-ground dry biomass (43.16 g∙pot−1) during the maturity growth period when compared with the control check (CK) treatment. The MS + Pb and CM + Pb treatments increased the exchangeable Pb fractions in the soil, but had a limited effect on Pb accumulation in wheat grains compared with the Pb treatment. In contrast, the SB + Pb treatment effectively increased soil pH and TOC, while decreasing the fraction of exchangeable Pb forms and increasing the oxidizable and residual Pb fractions, compared with the Pb treatment. Moreover, the MW + Pb treatment also increased the soil pH and CEC, displaying the potential to increase soil TOC, in addition to substantially modifying the portioning of Pb from exchangeable forms to less bioavailable fractions. Both the MW and SB amendments significantly reduced Pb concentrations in wheat grains (0.49 and 0.70 mg∙kg−1,∙respectively), resulting in increased above-ground dry biomass (51.59 and 54.12 g∙pot−1, respectively). In summary, the application of organic amendments, especially MW, could be an effective measure for enhancing Pb immobilization in polluted soils, thereby reducing its uptake and translocation to crops.

An Investigation into the Effects of Organic Amendments in a Saline Environment on Soil Chemical Characteristics, Growth, and Yield of Rice in the South of Senegal

Context of the Study: The use of organic amendments could help increase the resilience of lowland rice in Lower Casamance to salinity. The aim of this study was to test the effect of different organic amendments (biochar and compost) on the salinity tolerance of lowland rice in Basse Casamance.
 Objective: The aim was to test the effect of different organic amendments on the salinity tolerance of rice in the lowlands of the villages of Selecky and Essyl in Lower Casamance.
 Methodology: A split-plot design was adopted with two factors: the type of organic amendment with 4 treatments (biochar, compost, compost + biochar and the control) and salinity with two treatments (salted and unsalted zones). These treatments were repeated 3 times in two consecutive years, 2020 and 2021, at the Selecky and Essyl sites. Physico-chemical characteristics as well as rice growth and production parameters were studied.
 Results: In the saline zone, soil amendments significantly increased the number of tillers and the height of rice plants compared with controls (p<0.05). Average rice yield and plant biomass were significantly higher in the amended plots at Selecky in both experimental years (p<0.05). At Essyl, on the other hand, height, number of tillers, rice yield and plant biomass were lower in the 2nd year of experimentation. Organic amendments had a significant effect (p<0.05) on rice production and yield parameters in the salt zone.

Contrasting effects of different organic amendments on the microbial responses to extreme temperature changes

Soil organic amendments can change microbial communities, potentially impacting their resilience to environmental stresses and, consequently, their transformation of soil carbon and nitrogen. While several studies have investigated the impact of a few organic amendments on microbial resilience to stresses in the form of absolute change in environmental conditions, the potential stress effects of different rates of change have received much less attention. The rate of change in environmental properties such as temperature may induce different microbial stress responses, given the reliance of microbial defensive mechanisms on time-dependent signalling and activation processes. In this research, we explored the relevance of the rate of temperature change as a microbial stressor and evaluated the potential use of organic amendments in steering soil ecological response. We monitored the changes in microbial properties and concentrations of different carbon and nitrogen fractions to temperature change treatments of 2.5 and 30 °C/d after the application of three commonly available rural organic amendments to a podzol soil in a laboratory incubation study. Results showed significant effects of the temperature treatments on bacterial and total microbial DNA concentrations, as well as on dissolvable and insoluble carbon and nitrogen ratios regardless of the organic amendment treatment. Temperature impacts on respiration rates, priming rates and the concentration of soil hot water extractable carbon and nitrogen differed depending on the organic amendment treatment. Results demonstrated that compost-amended soils were least sensitive to the temperature treatments, while grasses and fermented grasses treatments were generally more sensitive while showing opposite responses. Our findings indicate that organic amendments might be utilized to manipulate the impact of environmental stresses on soil carbon and nitrogen concentrations, and highlight the need for future research to investigate the relevant ecological properties and mechanisms.

Organic amendment effects on cropland soil organic carbon and its implications: A global synthesis

Increasing soil organic carbon (SOC) content can promote soil health and crop yield. Organic amendment application is a common practice to accelerate soil carbon sequestration in cropland. The effects of different organic amendments (e.g., compost, slurry) on SOC are uncertain. Previous studies have investigated SOC response to environmental factors but not well addressed the effect of organic amendment characteristics (e.g., source, liquid/solid form, pH). Depending on 1,972 comparisons from 424 articles, we undertook a meta-analysis approach to explore organic amendment effects on SOC content and the related influence factors. The results show that organic amendment addition increased SOC by an average of 26.9% (or 5.1 Mg C ha−1). Specifically, organic amendments can enhance SOC over the long term (>20 years) or within 1.0 m depth. Organic-residue inputs increased more SOC in regions with an arid climate, alkaline soils, or no-mineral nitrogen application soils than the humid climate regions, acidic soils, and nitrogen application soils, respectively. Sewage sludge and municipal solid waste as organic amendments led to high SOC. The organic amendments' pH and liquid/solid form caused significant differences in SOC accumulation. Amendments with a relatively low carbon content or rich nitrogen content have great potential to increase SOC storage. Our results illustrate the importance of amendment characteristics when estimating the potential of organic amendment addition to soil carbon accumulation. This study highlights that amendment application might be a sustainable strategy to increase soil carbon storage while promoting organic waste utilization.

Effect of Different Organic Amendments on Growth, Yield and Quality of Broccoli (Brassica oleracea var. italica)

To study the effect of different organic amendments on growth, yield and quality of broccoli a field experiment was conducted during 2021–2022 in the Agriculture Research Farm, Lovely Professional University, Punjab A Factorial Randomized Block Design (FRBD) with two factors was used. Factors 1 and 2 are varieties (V1: Palam Vichitra and V2: Palam Kanchan) and biofertilizers (T1: Phosphate Solubilizing Bacteria @ 2 % + Azotobacter @ 2 %, T2: Phosphate solubilizing @ 2 %, T3: Azotobacter @ 2 %, and T0: Control). A total of eight treatments were used, i.e., T1V1 (Palam Vichitra X Phosphate Solubilizing Bacteria @ 2 % + Azotobacter @ 2 %), T2V1 (Palam Vichitra X P.S.B @ 2 %), T3V1 (Palam Vichitra X Azotobacter @ 2 %), T0V1 (Palam Vichitra X Control), T1V1 (Palam Vichitra X Phosphate Solubilizing Bacteria @ 2% + Azotobacter @ 2 %), T0V1 (Palam Kanchan X Phosphate solubilizing bacteria @ 2 %), T3V2 (Palam Kanchan X Azotobacter @ 2 %), T0V2 (Palam Kanchan X Control). The experiment reveals that among all treatments like growth, quality and yield parameters T1 showed the best result for V1 and in V2, T3 showed the best result for almost all the parameters. Floral bud initiation was early when treated with T1 in both the varieties, i.e., V1 (63 DAT) and V2 (63.67 DAT). Days to harvest were the same for all the treatments in V1 (90 DAT) and in V2, T1 (90 DAT) took the least amount of time for harvesting. It can be concluded that, combination of Azotobacter @ 2 % with other organic amendments and treatment T1 give higher yield and better quality of broccoli.

Effects of soil solarization combined with manure-amended on soil ARGs and microbial communities during summer fallow

Soil solarization (SS) is a technique for managing pathogens and weeds, which involves covering with transparent plastic to increase soil temperature during summer fallow (SF). However, SS also alters the diversity of bacterial communities. Therefore, during SF, various organic modifiers are used in combination with SS to improve its efficacy. Organic amendments may contain antibiotic resistance genes (ARGs). Greenhouse vegetable production (GVP) soils are vital to ensure food security and ecological balance. However, comprehensive study on the effects of SS combined with different types of manure on ARGs in GVP soils during SF remains unclear. Therefore, this study employed high-throughput qPCR to explore the effects of different organic amendments combined with SS on the abundance changes of ARGs and mobile genetic elements (MGEs) in GVP soils during SF. The abundance and diversity of ARGs and MGEs in GVP soils with different manure fertilization and SS decreased during SF. Horizontal gene transfer via MGEs (especially integrases 45.80%) induced by changes in environmental factors (NO3−-N 14.7% and NH4+-N) was the main factor responsible for the changes in ARGs. Proteobacteria (14.3%) and Firmicutes were the main potential hosts of ARGs. Network analysis suggested that Ornithinimicrobium, Idiomarina and Corynebacterium had positive correlations with aminoglycosides, MLSB, and tetracycline resistance genes. These results provide new insights to understand the fate of ARGs in the GVP soils by manure-amended combined with SS during SF, which may help to reduce the spread of ARGs.

Evaluation of Vegetative Development of Quinoa under Water Stress by Applying Different Organic Amendments

Prolonged drought periods, increasingly occurring worldwide due to global climate change, could affect the growth and productivity of both traditional and climate-resilient crops, including quinoa. Specifically, the vegetative growing cycle of this species is highly sensitive to drought conditions. In this context, using organic amendments could help plants cope with drought due to their ability to enhance soil water status. So, the current study aimed to investigate the effect of different organic amendments, i.e., two biochars (from woodchips and vineyard prunings) and a vermicompost (from cattle manure), applied to the soil alone and mixed at 2% rate (w/w), on the vegetative development of quinoa (cv. Titicaca), during which a period of water stress was imposed from the twelve-leaf stage to the bud stage. A set of growth-related parameters were measured both during and at the end of the experiment, along with a set of water-related parameters, at the end of the water-stress period and after soil re-watering. The results showed that woodchip biochar, both alone and mixed with vermicompost, significantly affected plant growth during the water-stress period, also allowing a quicker recovery once drought conditions ended. Indeed, the leaf number and area, SPAD index, leaf and stem fresh weight, and dry matter content in plants treated with woodchip biochar, alone and mixed with vermicompost, were higher than vineyard pruning biochar, alone and mixed with vermicompost and similar to the well-watered control plants. Similar results were observed considering the yield contributing traits detected at the end of the experiment, including the main panicle length, number of sub-panicle, as well as fresh weight and dry matter content of both panicle and sub-panicles. Additionally, the water-related parameters, especially the low turgid weight to dry weight ratio of woodchip biochar treated plants, showed evidence of better growth than vineyard pruning biochar. At the end of the experiment, the WUE of plants treated with woodchip biochar and vermicompost, both alone and mixed, was higher than vineyard pruning biochar alone and mixed with vermicompost. Among the tested organic amendments, woodchip biochar alone and mixed with vermicompost positively affected the vegetative growth response of quinoa under water-stress conditions.

Effect of different organic amendment on some properties of oasis soil (Saharan region of Touggourt - Algeria)

Local farmers combine several methods to manage soil organic matter: improve the quality and integrate other processes of managing the fertility of cultivated soils. The purpose of this work is to evaluate the effects of different organic amendments (OA) on any physico-chemical properties of the soil such as: pH, electrical conductivity (EC) and organic matter (OM). The amendments are: palm compost and manure (CPM); palm compost and reed (CPR); palm compost and reed + manure (CPRM); ovine manure (Om) and unamended soil (Ctl). The choice of materials is based on the idea of valorizing palm groves waste (palms and reeds) with ovine manure. The trial is conducted on randomized complete block design where two levels of soil samples are taken two months apart: S0 (day zero), Sin (initial sampling before application of amendment) then, S1, S2 and S3 until the end of cropping cycle. Obtained results show that all different OA increase the pH and decrease the EC of the soil after two months of application (S1) compared to the value of the initial sampling (Sin), which demonstrates the very highly significant effect of time on both parameters in the surface horizon. For the OM an incessant increase during the assay period was noticed where Om and CPR have marked the highest values during the third sampling (S3). This proved that the prepared composts from oasian wastes have an effect in improving soil properties over time. From an economic point of view, CPR showed results of OM that are similar of Om, which is considered as the most used and expensive manure in the region. Keywords: Compost; Oasis; Organic amendment; Valorization; Wastes

Mitigating Methane Emission from the Rice Ecosystem through Organic Amendments

Tamil Nadu in particular is a key rice-producing region in peninsular India. Hydrochemistry, viz., redox potential (Rh), soil temperature and dissolved oxygen (DO), of rice soils can determine the production of greenhouse gas methane (CH4). In recent decades, the cultivation of crops organically became a viable option for mitigating climate change. Hence, this study aimed to investigate the effects of different organic amendments on CH4 emission, Rh, DO, and soil and water temperature (T) in relation to the yield of paddy. The treatments composed of viz., control, blue-green algae (BGA), Azolla, farm yard manure (FYM), green leaf manure (GLM), blue-green algae + Azolla, FYM + GLM, BGA + Azolla + FYM + GLM, vermicompost and decomposed livestock manure. With the addition of BGA + Azolla, the highest reduction in CH4 emission was 37.9% over the control followed by BGA. However, the same treatment had a 50% and 43% increase in Rh and DO, respectively, over the control. Established Pearson correlation analyses showed that the CH4 emission had a positive correlation with soil (r = 0.880 **) and water T (r = 0.888 **) and negative correlations with Rh (r = −0.987 **) and DO (r = −0.963 **). The higher grain yield of 26.5% was associated with BGA + Azolla + FYM + GLM application. Our findings showed that there are significant differences in CH4 emissions between different organic amendments and that hydro-parameters may be a more important controlling factor for methane emissions than temperature. The conclusion has been drawn based on valid research findings that bio-fertilization using BGA and Azolla is an efficient and feasible approach to combat climate change, as it assists in reducing methane emissions while simultaneously boosting crop yield by fixing nitrogen into the soil in the studied agro-climatic zone.

Effect of organic amendments in seed production of radish (Raphanus sativus)

The present study was carried out at the Vegetable Research Farm, Department of Vegetable Science, Dr. Y S Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh during the rainy (kharif) season of 2019, 2020 and 2021 to evaluate the effect of different organic amendments in seed production of radish (Raphanus sativus L.) cv. Chinese Pink. The experiment was laid out in Randomized Block Design, consisting of seven treatments with three replications. The treatments were: T1, Control; T2, FYM @20 t/ha; T3, Vermicompost @8 t/ha; T4, FYM @10 t/ha + vermicompost @4 t/ha; T5, FYM @20 t/ha + Vermiwash @1:1 (v/v - water + vermiwash) spray; T6, Vermicompost @8 t/ha + Vermiwash @1:1 (v/v - water + vermiwash) spray; T7, FYM @10 t/ha + Vermicompost @4 t/ha + Vermiwash @1:1 (v/v – water + vermiwash) spray. Pooled data of three consecutive years revealed that application of T7 recorded maximum plant height (127.30 cm), number of branches per plant (9.89), highest number of pods per plant (690.57), more seed yield per plant (30.35 g) and seed yield per hectare (5.93 q). This treatment also resulted in maximum 1000-seed weight (11.83 g), germination (94.77%), seed vigour index-I (2420.51) and seed vigour index-II (669.33) along with highest net return (`458135.70/ha) and benefit:cost ratio (3.40).

Effect of Different Organic Amendments on Actual and Achievable Yields in a Cereal-Based Cropping System

Soil fertility is at risk in intensive cropping systems when using an exclusive regime of inorganic fertilisers without returning sufficient organic matter to the soil. Our objective was to evaluate the long-term effects of commonly used organic amendments interacting with different rates of inorganic nitrogen fertiliser on crop yields of winter wheat. Yield data from winter wheat were collected for five seasons between 2013 and 2019 from a continuous field trial based at Rothamsted Research, SE England. Organic amendments (anaerobic digestate, compost, farmyard manure, and straw at a rate of 0 and 2.5 ton C per hectare) and five rates of inorganic nitrogen fertiliser (NH4NO3 at 0, 80, 150, 190, 220 kg N ha−1) were applied to winter wheat grown in an arable rotation. At the same inorganic N rate, grain yields for the different organic amendment treatments (excluding the straw treatment) were statistically similar but significantly greater than the unamended control treatment. The nitrogen rate required for optimum yields tended to be lower in plots receiving a combination of organic amendments and mineral fertiliser. Based on the observed and modelled response functions, organic amendments excluding straw increased maximum achievable yields compared to non-amended controls. The size of the effect varied between seasons and amendments (+4.6 to +19.0% of the control yield), increasing the mean maximum achievable yield by 8.8% across four seasons. We conclude that the application of organic amendments can increase the yield potential in winter wheat substantially over what is achievable with inorganic fertiliser only.

The influence of compost amendments on bioaccumulation of potentially toxic elements by pea plant cultivated in mine degraded soils

Potential toxic metal (PTE) accumulation in soil and water is one of the major sources of food crop contamination. PTE remediation from soil can be enhanced by the addition of organic matter to the growing media. An experiment was carried out to investigate the effect of different organic amendments on the accumulation of PTEs in pea plant grown on mine degraded soils. Mining soils from chromite mine (CM), soap stone mine (SSM), manganese mine (MM), and quartz mine (QM) were mixed with vermicompost (VC), leaf mould (LC), and spent mushroom compost (SMC) along with garden soil at 1:1:1 ratio. Various growth and yield-related attributes of pea plant as well as PTE concentrations in soil and plants were studied. The highest Cd (2.62 mg kg−1) and Cr (13.6 mg kg−1) concentration was reported in CM soil, while Pb (23.3 mg kg−1) and Mn (59.2 mg kg−1) concentration in SSM and MM soil, respectively. Mining soils significantly reduced the plant growth and yield, while organic amendments reduced the PTE availability and increased pea plant growth. Comparing the various organic fertilizers used, it was observed that VC efficiently reduced Cd, Cr, Pb, and Mn uptake by pea plant, subsequently, improved pea plant growth and productivity. In order to assess the effects of various amendments on PTE health risk reduction, various risk indices including plant tranfser factor, average daily intake, health risk, target hazard quotient, and target cancer risk were also calculated and the results revealed that application of compost particularly VC significantly reduced the dietary intake and health risks of PTEs.

Long-Term Effects of Organic Amendments on Carbon Stability in Clay–Organic Complex and Its Role in Soil Aggregation

Clay–organic complexes (COC) impart chemical and physical protection to soil carbon (C). In the present study, the aim was to assess the long-term effects of different organic amendments on C stability in COC, distribution of the aggregates, C concentration in the aggregates and labile organic C fractions in the inceptisols located at the research farm situated in the semi-arid sub-tropical climate of India. The results showed that the COC, the percentage of large macroaggregates (LMA) (>2 mm) and the C associated with the aggregates decreased through the soil depths, whereas the other size fractions of soil aggregates (<2 mm) showed an increasing trend. The COC was significantly higher (4.4 times) in soil treatments where farmyard manures (FYM), green manure (GM) and biofertilizers (BF) were applied together (FYM + GM + BF). The organic amendments increased the proportion of LMA over control (no application of organic amendments) to a magnitude of 83 to 101% and the C associated with LMA to a magnitude of 0.48 to 9.8% over control in surface soil. On average, the combined application of FYM, GM and BF exhibited higher C accumulation in almost all soil aggregate fractions, except microaggregates (mA), i.e., (0.25–0.053 mm) size fractions, where application of FYM alone recorded the highest value. Averaged over soil depths, the particulate organic C (POC), dissolved organic C (DOC) and potassium permanganate oxidizable C (POXC) were significantly higher under integrated organic treatments than individual amendments. The significantly higher correlation between COC and the percentage of LMA and aggregate-associated C implied their direct role in soil aggregate formation and their stability. The carbon stability, i.e., retention time of humus in soil, was significantly correlated with soil organic carbon, dissolved organic carbon, particulate organic carbon, potassium permanganate oxidizable C, C mineralization (Cmin), glomalin-related soil protein (GRSP), macroaggregate (MA)-associated C and rice equivalent yield (REY). Overall, the data suggest that the combined application of FYM + GM + BF promotes soil quality under rice–wheat rotation in inceptisols in semi-arid sub-tropical India.

Organic amendments from recycled waste promote short-term carbon sequestration of restored soils in drylands

Soils are considered as a major reservoir for terrestrial carbon and it can act as a source or sink depending upon the land management activities. In semi-arid areas, the natural recovery of soils degraded by mining activities is complicated. A possible solution to recover soil quality and functionality, plant cover and carbon sequestration capacity could be the application of organic amendments. This work focuses on a restoration carried out in 2018 by applying with different composted organic amendments (stabilized sludge, gardening and greenhouse waste) in a limestone quarry under semi-arid climate (SE Spain). The objective was to evaluate the effects of different organic amendments on net CO2 exchange in two microcosms: soil-Stipa tenacissima and soil-spontaneous vegetation. Soil physical and chemical properties, environmental and ecological variables and their interrelationship were studied in amended and unamended soils. The results obtained under soil-forming factors in the study area showed an increase in soil organic carbon and nitrogen content, improved moisture and plant growth, and plant canopy development in amended soils. Soil moisture, soil temperature and plant cover significantly influenced net CO2 exchange. In general, microcosms with S. tenacissima showed higher carbon sequestration rates than soils with only spontaneous plant cover. Soils treated with a vegetable-only amendments showed higher plant cover and CO2 fixation rates after significant rainfall. On the other hand, the plots treated with sludge compost presented more soil respiration than photosynthesis, especially in the wet seasons. Soils with sludge and greenhouse compost mixed had higher CO2 fixation rates than soils restored with a mixture of sludge and garden compost. Soils with greenhouse waste compost showed CO2 fixation in the microcosm with plants in all campaigns, being the best treatment to promote atmospheric CO2 sequestration in soil restoration.

Effects of Different Organic Amendments on Soil Improvement, Bacterial Composition, and Functional Diversity in Saline–Sodic Soil

The agricultural productivity of farmland in Northeast China’s Liaohe Plain is restricted by the salinity and sodicity of the soils, which have additionally low organic matter content. In order to improve saline–sodic soils, organic amendments are frequently applied. Our objective was to clarify how different organic amendments affect the diversity and composition of soil microbes, as well as how these factors are related to crop yield. In 2020–2021, we conducted an experiment with different organic amendments. The treatments included the application of crop residue incorporation (SR), lignite humic acid (LHA; 6 ton/ha), or cow manure (FM; 30 ton/ha), and a control (CK). The results show that, compared with CK, the content of SOM in soil treated with organic amendments increased by 5.3–7.4 g/kg; the available potassium (AK) of the LHA treatment was significantly higher than that of the FM and SR treatments by 32.17 and 42.79 mg/kg, respectively; and the available phosphorus (AP) of the LHA treatment was significantly higher than that of the SR treatment by 7.19 mg/kg. The pH and EC1:5 values of the LHA treatment were significantly lower than those of CK by 1.36 units and 0.2 mS/cm, respectively. The application of organic amendments and changes in environmental conditions also significantly affected community structure and increased soil microbial richness and diversity. SR treatment increased the abundance of Acidobacteria. Further FAPROTAX (Functional Annotation of Prokaryotic Taxa) analysis showed that organic amendments can increase the abundance of microbes involved in the carbon and nitrogen cycle processes, such as aerobic_ammonia_oxidation, aerobic_chemoheterotrophy, nitrification, etc., which increases the kernel number per row and increases crop yield. LHA can increase the microbial abundance of the nitrogen cycle and reduce soil carbon mineralization, while also increasing soil nutrients and crop yield. This study provides a comprehensive understanding of the application of organic amendments in saline–sodic cultivated land.

Effects of Different Organic Amendments on Maize (Zea Mays L.) Growth in Salt Affected Soil

Salinity stress is the most notorious among all abiotic stresses. It hampers the growth and productivity of crops via ionic imbalance, disturbance in the metabolic process and specific ions toxicity. The necessity of time is to introduce better organic amendment rates for its mitigation in cereal crops, especially maize. Therefore, a pot experiment was performed in the wirehouse of the Saline Agriculture Research Centre (SARC), University of Agriculture, Faisalabad to evaluate the effect of farmyard manure and compost application rates in saline soil. A hybrid maize variety (Monsanto DK-6789) was sown and recommended doses of NPK were applied. Organic amendments (FYM and Compost) with their rates (recommended, 25% increased dose of recommended and 50% increased dose of recommended) were applied to assess the growth of hybrid maize with salinity levels (Control < 2dS m-1, moderate salinity_5dS m-1, High salinity_10dS m-1). Seven treatments each with three replicates were carried out by using Complete Randomized Design (CRD). The results of the study indicated that T4 (50% increased farmyard manure) and T7 (50% increased compost) were significantly varied in controlling the shoot and root length, shoot and root fresh weight and dry weight of maize over control at <2, 5 and 10 dS m-1 EC. A significant increase of 32, 28 and 39% in chlorophyll contents of maize validated the efficacious functioning of T4 over control for alleviation of <2, 5 and 10 dS m-1 salinity. Similarly, significant enhancement of 48, 39 and 84% in root fresh weight also declared that T7 was a better treatment under <2, 5 and 10 dSm-1 salinity. In conclusion, T4 and T7 can be used and recommended for better alleviation of salinity stress in maize. More experiments are suggested at the field level by using these 2 application rates of farmyard manure and compost for declaration of modified amendment for salinity stress mitigation.

Fertilizer Potential of Organic-Based Soil Amendments on cv. Sangiovese (V. vinifera L.) Vines: Preliminary Results

The intensification of highly specialized viticulture has led to a dramatic decrease of soil fertility that can be restored by increasing soil organic matter using organic fertilizers. The aim of the present experiment was to evaluate the effect of different organic amendments on vine vegetative growth and nutritional status, soil N availability and microbial biomass, as well as on yield and grape quality. The experiment was carried out in 2020 and 2021, on cv. Sangiovese (Vitis vinifera L.) vines grafted on 110 Richter (V. berlandieri × V. rupestris) planted in February 2019. Plants were fertilized yearly in spring with (1) mineral fertilization (MIN), (2) municipal organic waste compost (MOW), and (3) sewage sludge compost (SS). The application of SS increased nitrate availability in both years, while the supply of organic matter (no matter the source) enhanced soil microbial biomass content. Plant nutritional status was in the optimal range for all treatments, with an increase of N in SS and K in MOW. Fruit yield in 2020 was not influenced by treatments, while in 2021 it was enhanced by MIN and MOW, which also induced a higher berry quality. Plant vegetative growth was stimulated by the application of SS. In conclusion, from these preliminary results we observed a higher N availability as a consequence of SS supply that resulted in a higher plant biomass, but reduced yield and berry quality, supporting the theory that for vineyards, N should be carefully managed to reach an equilibrium between vegetative and reproductive activity.

Effects of different organic amendments on soil pore structure acquired by three‐dimensional investigation

AbstractThe application of organic amendments is an important way to improve soil structure. However, the differences in soil pore properties after adding various organic materials are not fully available, which is important for selecting the most suitable material for soil improvement. In this study, soil pore structures in a field experiment amended with different organic materials (maize straw [MS], cattle manure, mixture of MS and cattle manure, biochar, woody peat, and polyacrylamide [PAM]) were determined by digital image analysis and three‐dimensional (3D) investigation, and their changes were quantitatively evaluated. The results showed that all organic material applications reduced the soil bulk density and increased the field capacity and water‐stable macroaggregate content. The 3D information about the soil pore structure showed that MS return was closely related to pore shape parameters. Soil treated with PAM had a low channel and throat number, long channel length and large throat area, all of which affect soil solute migration and crop root growth. A straw and organic fertiliser mixture changed the medium and large porosity (>500 μm) percentage from 1.1% to 9.7%, and the connected/isolated porosity ratio (C/I ratio) increased by 4.7 times. Taken together, our results indicate that the application of organic amendments can effectively improve the soil microstructure in fluvo‐aquic soils of the Huanghuaihai Plain in China, which is consistent with macroscopic physical properties such as bulk density and field capacity. PAM addition can promote the redistribution of air, water and nutrients in the soil. Straw returning can significantly affect the soil pore shape. Among all organic amendments, a straw and organic fertiliser mixture had the most obvious effects on the soil structure, especially on improving soil connectivity.Highlights Computed tomography and digital image processing used to visualise and quantify pore structure of soil treated with organic materials. Applications of various organic amendments reduced bulk density of fluvo‐aquic soil. Field capacity and water‐stable macroaggregates were increased. Straw and organic fertiliser improved soil porosity and connectivity and increased numbers of macropores.