Rice Fallow Research Articles

Lowland Integrated Crop–Livestock Systems with Grass Crops Increases Pore Connectivity and Permeability, Without Requiring Soil Tillage

Enhancing integrated crop–livestock systems (ICLSs) to improve land-use efficiency is a critical goal. Understanding the ICLS impacts on lowland soils is key to sustainable agricultural practices. Our objective was to test whether adopting ICLSs in lowlands improves soil structure, pore connectivity, and water and air permeability. This study was conducted in a long-term field trial, consisting of the following production systems with flood-irrigation rice: rice–fallow–rice, under conventional tillage and absence of grazing (RFR-ct); rice-grazed ryegrass–rice, under no-tillage and grazing (RGrR-nt); rice-grazed ryegrass–soybean-grazed ryegrass–rice, under no-tillage and grazing (RGrS/RGrR-nt); and a grazed pasture-consortium (winter) and succession field (summer), with no-till rice every 4 years (P4R-nt). Core samples were collected after grazing (October 2018), harvesting (March 2019), and grazing (October 2019). We analyzed soil air permeability, saturated hydraulic conductivity, pore connectivity by computed tomography. Soil tillage in a semi-direct system generated discontinuous porosity. Systems with intense trampling or less surface protection are affected by shearing on topsoil, reducing pore continuity. ICLSs are mainly composed of ryegrass–rice mitigated the harmful effects of trampling, and improved soil structure and functioning. Systems without soil tillage exhibited higher pore connectivity and pores with vertical orientation. Finally, soil tillage is not required to improve structural quality in ICLSs.

Rice Fallow Pulses for Agricultural Potential for South Asian Region

Rice fallows refer to lowland areas where rice is cultivated during the monsoon (kharif season) is left unplanted during the winter season (rabi) due to various factors. These include the early cessation of monsoon rains which resulted in soil moisture stress during winter season; waterlogging and excessive moisture in November/December, led to unsuitable for winter crops; the absence of suitable varieties for late planting at winter season and socio-economic issues such as damage by stray cattle or blue bulls. India accounts for a significant majority of about 79% of South Asia's total rice fallows which amount to 11.65 million hectares out of the region's total of 15.0 million hectares. The review assess the scenario of rice fallow pulses, production technologies and its constraints in the present trend.

Evaluation of rabi season sesame productivity from graded nutrient doses and tillage regimes in rice fallows of southern plateau and hills region of the Indian sub-continent.

Only scattered information is available on the tillage and nutrient management information for the sesame crop following rice in the literature. Sesame as an edible oil yielding crop with high levels of unsaturated fatty acids has high international demand due to superior health benefits. Being a small seeded crop, it requires standard tillage and nutrient management to obtain optimum productivity under rice fallow ecologies. As a sequential crop after rice harvest, the tillage and nutrient management practices followed for the preceding rice have astounding effects on the succeeding sesame crop. To better understand and manipulate the agro ecology in the rice fallow culture, it is necessary to study the behaviour of sesame cultivars, in relation to the tillage requirements and macro nutrient factors that have a bearing on the productivity. The aim of this work was to evaluate the productivity of rice fallow sesame in the southern plateau and hills regions of the Indian sub-continent (Tamil Nadu) with a hypothesis that tillage and nutrient management would immensely benefit the sesame crop. Field experiments were conducted at TNAU, Tamil Nadu Rice Research Institute, Aduturai, Tamil Nadu during 2019-2020 and 2020-2021 with tillage practices (reduced tillage, conventional tillage and zero tillage) and fertilizer doses (zero percent RDF, 25% RDF, 50% RDF, 75% RDF and 100% RDF) in a split plot design replicated thrice. The results have clearly indicated that the performance of rice fallow sesame was poor under zero till conditions as the sesame crop is poorly adapted leading to a yield penalty up to 68%. A total of 75% RDF has yielded statistically similar yield to that of 100% RDF to the rice fallow sesame. Further, neither the oil content nor the fatty acid composition was modified by tillage and nutrient management regimes.

Effect of Varieties, Planting Densities and Phosphorus Levels on Seed Yield and Post-Harvest Soil Physico-Chemical Properties of Rice Fallow Redgram

Aim: To assess the effect of varieties, planting densities and phosphorus levels on yield and physico-chemical properties of post -harvest soil in rice fallow redgram. Study Design: The experiment was laid out in strip-split plot design with three varieties as vertical factor viz., V1: ICPV-21333, V2: ICPV-21444 and V3: ICPV-; two levels of spacings viz., P1: 0 kg P2O5 ha-1, P2: 25 kg P2O5 ha-1, P3: 37.5 kg P2O5 ha-1 and P4: 50 kg P2O5 ha-1. Place and Duration of Study: RL 12, block 3 and 4, International Crops Research Institute for Semi-Arid Tropics (ICRISAT), Patancheru, Hyderabad, during rabi, 2022-23 and 2023-24. Methodology: The investigation consisted of three varieties as vertical factor, two levels of spacing as horizontal factor and four levels of phosphorus as sub-plots with a total of 24 treatment combinations and replicated thrice. Data recorded on various parameters was subjected to scrutiny by ANOVA technique for split plot design concept. Data was subjected to analysis of variance procedures as outlined for strip-split plot design. Results: From this investigation, it was found that seed yield was significantly higher with the variety ICPV-21333 (812 and 750 kg ha-1), but remained statistically comparable to ICPV-21444. Among the spacings, it was highest with 30 cm x 10 cm (792 and 740 kg ha-1) and with respect to phosphorus levels, crop fertilized with 50 kg P2O5 ha-1 registered higher seed yield (797 and 740 kg ha-1) but, was statistically at par with 37.5 kg P2O5 ha-1. Available post- harvest soil N, and K2O was not influenced by the various treatments, but available P2O5 was significantly influenced by phosphorus levels. Higher available P2O5 was observed with the application of 50 and 37.5 kg P2O5 ha-1 kg P2O5 ha-1, while the lowest status was noticed with 0 kg P2O5 ha-1. Similarly, bulk density, pH, EC and OC were not significantly influenced by varieties, spacings and phosphorus levels and due to their interaction during both the years of study.

Residual Effect of Rice-fish Based Organic Nutrient Management Approaches on Rice Fallow Blackgram Productivity Enhancement in Cauvery Delta Zone of Tamil Nadu

Background: A field experiment was conducted during the rice fallow season of 2023 and 2024 (January to March) at Tamil Nadu Rice Research Institute (TRRI), Aduthurai, Tamil Nadu to study the residual effect of rice-fish-based organic nutrient management practices adopted in rice on succeeding blackgram grown as rice fallow. Methods: The experiment was carried out using randomized block design (RBD) with eleven treatments viz., T1- No Green manure-Rice crop alone (RDF), T2-Green manure- Rice crop alone (PSB+KSB+ZSB), T3-T2+Nanourea, T4-Green manure- Rice crop (PSB+KSB+ZSB) + Fish, T5-T4 + Nano urea,T6- Green manure- Rice crop (PSB+KSB+ZSB) + Fish + Azolla, T7-T6 + Nano urea, T8-Green manure-Rice crop (PSB+KSB+ZSB) + Fish + Duck, T9- T8+Nano urea, T10- Green manure- Rice crop (PSB+KSB+ZSB)+ Fish + Azolla + Duck, T11- T10+Nano urea. The treatments were replicated thrice. The blackgram variety ADT 6 was used as a test crop. Result: The results revealed that among the different organic nutrient management approaches followed in the rice-fish based farming system, the residual effect of Green manure- Rice (solubilizing bacteria such as PSB, KSB and ZSB) + Fish + Azolla + Duck (T10) resulted in higher plant height, DMP, LAI and SPAD value in blackgram. Similarly, the highest root length (19.43 cm), root dry weight (1.10 g), root volume (10.68 g/cc), nodule plant-1at 20 DAS (13.82) and nodule plant-1at 40 DAS (22.97) were also obtained with the same treatment. By virtue of higher growth and yield parameters, more number of pods plant-1 (26.88) and seeds pod-1 (7.73), grain yield (789 kg ha-1) and Halum yield (2136 kg ha-1) of blackgram were obtained in the residual treatment of the residual effect of Green manure- Rice (solubilizing bacteria such as PSB, KSB and ZSB) + Fish + Azolla + Duck (T10). The available soil nutrients at 20 DAS of blackgram were higher in Green manure- Rice (solubilizing bacteria such as PSB, KSB and ZSB) + Fish + Azolla + Duck (T10). Due to higher blackgram yield, the same treatment achieved higher gross return (Rs.41561 ha-1), net return (Rs.30156 ha-1) and BCR (3.64). The study also indicated that the trench (300 m3) dug in rice fields for fish rearing provided sufficient moisture for rice fallow blackgram and thereby evaded the terminal stress.

Yield Trait and Stability of Chickpea Genotypes for Intensification of Drought‐Prone Rice Fallows of South Asia

ABSTRACTThere is a need for increasing cropping intensity in South Asia including India to ensure food security of burgeoning population. Accordingly, increasing cropping intensity in rainfed rice fallows can be a futuristic strategy. Identification of suitable cultivar and exploration of genetic variability of specific crops/traits are imperative for genetic improvement, drought resistance and yield gain in rice fallows. We evaluated the morphophysiological, yield traits and stability of 15 chickpea genotypes in randomised complete block design for three consecutive years on a drought‐prone rainfed condition of Fluvisol in Kanpur, India. Among genotypes, ‘IPC 2014‐55’, ‘IPC 2015‐44’ and ‘IPC 2011‐92’ had 2%–10% higher relative water content (RWC) over ‘ICC‐92944’ (check cultivar). These genotypes did not differ for total chlorophyll content, root dry weight and nodule dry weight with ‘ICC‐92944’ and ‘KWR 108’ (wider adaptable cultivar of the region). The nitrogen balance index was higher in ‘IPC 2011‐92’, ‘IPC 2014‐88’ and ‘IPC 2014‐55’ by 5%–44% over check cultivar (p < 0.05). The membrane stability index was higher for ‘IPC 2014‐55’ (30%, p < 0.05) and ‘IPC 2011‐92’ (17%, p < 0.05) than ‘ICC‐92944’. ‘IPC 2011‐92’, ‘IPC 2014‐88’ and ‘IPC 2014‐55’ (3 years mean) had 3%–24% higher plant dry weight than ‘ICC‐92944’. Notably, ‘IPC 2014‐55’, ‘IPC 2015‐44’, ‘IPC 2014‐88’ and ‘IPC 2011‐92’ had higher yield attributes such as pods plant−1 by 9%, grain weight plant−1 by 13% and 100‐seed weight by 3% than ‘ICC‐92944’ and ‘KWR 108’ (mean of years). These genotypes had higher mean seed yield than ‘ICC‐92944’ by 23%–42% and ‘KWR 108’ by 7%–23% (p < 0.05). The yield of ‘IPC 2014‐55’, ‘IPC 2015‐44’, ‘IPC 2014‐88’ and ‘IPC 2011‐92’ were stable over years across variable soil and environmental condition as indicated by the genotype × year biplot. Membrane stability index, pods plant−1 and 100‐seed weight were the determinants for increased seed yield of chickpea under drought‐prone condition. Evidently, genotype ‘IPC 2014‐55’, ‘IPC 2015‐44’, ‘IPC 2014‐88’ and ‘IPC 2011‐92’ were better under rainfed rice fallows. These genotypes could be tested under specific drought condition for developing varieties and promoted in rice fallows of South Asia for yield advantage and drought resistance.

Piloting Pulse Producer Support System Through ICT Enabled Services for Enhanced Climate Resilience

Background: In peninsular India, the frequency of climate-related risks is significantly lowering agricultural productivity and farmers’ standard of living. Reducing losses in the agriculture sector requires precise and timely weather information, weather based advisories on crop production, protection and post-harvest. Disseminating agromet advisories directly to the farmers using ICT tools allows farmers to adopt appropriate corrective measures, minimize loss and ensure climate resilient agriculture. In this sense, the Tamil Nadu Agricultural University established an Automated Agromet Advisory Web cum Mobile App (TNAU-AAS) in 2018, which sends location, crop and stage specific agromet advisories directly to farmers’ mobile App. Methods: TNAU-AAS App was evaluated in pulse crops as “Piloting pulse produce support system through ICT enabled services” between 2019 and 2021 in three TNAU centers under three different eco systems namely irrigated (Coimbatore), rice fallow (Aduthurai) and rainfed (Kovilpatti). Pulse growing farmers were registered in this smartphone application for agromet advisory based response farming. Result: The TNAU-AAS App had delivered approximately 10-12 advisories to each farmer, tailored to their unique crop and stage during the cropping period. Survey results inferred that the farmers received timely notifications on their mobile phones, 2-3 days in advance, which assisted them in preplanning. Occurrences of pests and diseases were well aligned (68-83%) with TNAU- AAS recommendations and the climate vulnerability of non AAS farmers is more than AAS farmer. According to partial budget analysis, the irrigated, rice fallow and rainfed black gram farmers have gained Rs. 2800, Rs. 2300 and Rs. 1900 per ha, respectively. It is concluded that the ICT-enabled agromet advisory system guarantees timely alerts, boosts labor and land productivity, lowers input loss and shields crops from weather-induced pests and diseases as well as climatic variability risk.

Physiological Efficiency of Weeds in Rice Fallow Fields

Photosynthetic rate, Transpiration rate and Stomatal Conductance is measured in different weeds during July’2020 in rice fallows using IRGA- Photosynthesis system model Lci- T. We have chosen all the weeds at flowering to maturity phase and observed the data. Among the weeds analysed Parthenium hysterophorus has recorded very high Photosynthetic rate (µ molm-2 Sec-1)and there was difference with stage also, Flowering stage (165.28) has recorded a higher photosynthetic rate followed by vegetative (123.2) and maturity phase (118.72) and found that transpiration rate also followed the same trend. Even this has recorded more than the C4 crop photosynthetic rate for example Trianthema portulacastrum which has recorded a photosynthetic rate of 21.98, which was the next highest photosynthetic rate among the weeds recorded and as well as over C4 crops too. Among the grasses Paspalum sp., Echinochloa colona (7.81µ molm-2 Sec-1)) and Cynodon dactylon (4.2µ molm-2 Sec-1)) has recorded higher photosynthetic rate. Cyperus and Cyanodonhas recorded with lesser stomatal conductance and transpiration rate but has recorded higher photosynthetic rate which can thrive better in rainfeds also. Echinochloa has more transpiration rate and stomatal conductance among grasses and this might be due to their water loving nature. Boerhavia diffusa, Euphorbia hirta and Ruella tuberosa are recorded with lesser stomatal conductance. On critically analysing the weeds, it was observed that some weeds like Parthenium are reported with higher photosynthetic rate with lesser transpiration rate and stomatal conductance over better photosynthetic efficiency crop like maize and also this has resulted in the better withstanding ability to the water stress. Correlation analysis showed that photosynthesis and Transpiration rate are positively correlated but weak (r=0.28) and the regression equation is (Y=4.98+4.32(x)), photosynthetic rate and stomatal conductance are also positively correlated but weak (r=0.20) and the regression equation is Y= 20.36+17.04(X). Transpiration and Stomatal Conductance is positively and strongly correlated (r=0.57) and regression equation is Y=3.92+2.51(x).

Effect of Sowing Dates and Seed Priming on Agrometeorological Indices and Soil Moisture Regimes of Chickpea in North Central Plateau Zone NCPZ of Odisha

Background: field experiment entitled “Effect of sowing dates and seed priming on agrometeorological indices and soil moisture regimes of Chickpea in NCPZ of Odisha” was conducted at RRTTS, Keonjhar, Odisha, during the Rabi season for two consecutive years i.e., 2021-22 and 2022-23. Method: The field experiment was laid out in factorial RBD design with three replications and two factors. There were 3 dates of sowing in Factor A (D1-25 November, D2-5 December, D3- 15 December) and 5 moisture conservation practices in Factor B (M1- Control, M2- Seed priming with water for 8 hours, M3- Osmopriming (Seed priming with CaCl2 solution @0.5% for 8 hours), M4- Straw mulch@ 5t/ha and M5- Straw mulch@ 5t/ha +Seed priming with CaCl2 solution @0.5% for 8 hours). Seed priming controls the hydration of seeds that helps in the pre germinative metabolic activity of the seeds. So even if the soil has less moisture that will not affect the uniform and proper germination of the seeds. All together there were 15 treatment combinations. The test crop variety taken was JAKI-9218. Among the three dates of sowing, D2 (5th Dec) sowing recorded the tallest plants (41.47 cm). but were recorded in D1 (25 Nov) sowing. Early sowing on 25th November recorded the maximum number of primary and secondary branches and required a greater number of days to 50% flowering (41.8 days) and days to physiological maturity (101.1 days). Results: Among the moisture conservation practices, M5 (Straw mulch@ 5 t/ha+Seed priming with CaCl2 solution @ 0.5% for 8 hours) recorded the tallest plants, maximum number of primary and secondary branches, maximum number of days taken to 50% flowering (40.7 days) and days taken to physiological maturity (100.1 days), maximum number of pods per plant (44) and number of seeds per pod (3.62), grain yield (1812 kg/ha) and straw yield (218 kg/ha). This treatment recorded the minimum consumptive use of water (203.5 mm) and rate of moisture use (1.36 mm/day) but the moisture use efficiency was maximum (12.34 kg/ha-mm). Treatment M5 recorded the maximum growing degree days (2182°C day), heliothermal unit (15077°C day hrs), photothermal unit (22595°C day hrs) and heat use efficiency (0.94 kg/ha/°C) to reach maturity. Chickpea when combined with suitable date of sowing and moisture conservation practices for proper utilization of carry-over residual soil moisture in the rice fallows gives higher yield.

Green manuring reduces cadmium accumulation in rice: Roles of iron plaque and dissolved organic matter

In southern China, winter green manure is widely used in rice cropping systems for improving grain yields and soil fertility. Cd pollution has recently been reported in some of these paddy fields. Research on the in-depth understanding of how green manuring affects Cd absorption in rice is limited. This study aimed to investigate the impacts of different green manures, including single plantation and mixed plantation on the absorption of Cd by rice and explore the underlying mechanisms. Pot experiments demonstrated that compared with winter fallow–rice, green manuring treatments considerably decreased rice Cd content, promoted the conversion of bioavailable Cd fraction into a more stable form, induced the formation of iron plaque, and increased the content of humic-like fraction (HF) in soil dissolved organic matter (DOM). Treatment with mixed plantation resulted in a greater decrease in rice Cd content and an increase in HF and iron plaque contents than single plantation. Hydroponic experiments confirmed that both iron plaque and green manure-derived DOM significantly reduced the Cd content in rice seedlings. In conclusion, green manure incorporation is an efficient measure for the safe utilization of Cd-contaminated soil, and mixed plantation of different green manures exerts stronger effects.

Greenhouse Gas Emissions, Carbon Footprint, and Grain Yields of Rice-Based Cropping Systems in Eastern China

A multiple cropping system is beneficial for utilizing natural resources, while increasing the grain production and economic outputs. However, its impact on greenhouse gas emissions is unclear. The objective of this study was to evaluate the influence of rice-based cropping systems on methane (CH4) and nitrous oxide (N2O) emissions, the carbon footprint (CF), grain yields, and net economic returns in eastern China. Four treatments were applied: rice–fallow (as a control), rice–milk vetch, rice–wheat, and rice–rapeseed. Methane and N2O emissions were measured every 7 days via static chamber and gas chromatography methods from the 2019 rice season to the 2021 non-rice season. The CF was calculated based on the life cycle assessment. The results showed that multiple cropping systems significantly increased the annual grain yield by 1.2–6.4 t ha−1 and the annual CH4 and N2O emissions by 38–101 kg CH4-C ha−1 and 0.58–1.06 kg N2O-N ha−1, respectively. The average annual net returns for rice–wheat and rice–rapeseed were 131–150% greater than those for rice–milk vetch and rice–fallow. The annual CFs increased in the following order: rice–wheat (19.2 t CO2-eq ha−1) > rice–rapeseed (16.6 t CO2-eq ha−1) > rice–milk vetch (13.9 t CO2-eq ha−1) > rice–fallow (11.5 t CO2-eq ha−1). The CH4 emissions contributed to the largest share of the CF (60.4–68.8%), followed by agricultural inputs (27.2–33.7%) and N2O emissions (2.9–5.9%). Moreover, nitrogen fertilizer accounted for 65.6–72.4% of the indirect greenhouse gas emissions from agricultural inputs. No significant difference in the CF per unit grain yield was observed between the four rice-based cropping systems. The CF per net return of rice–wheat and rice–rapeseed significantly decreased by 37–50% relative to that of rice–fallow and rice–milk vetch. These findings suggest the potential to optimize rice-based cropping systems for environmental sustainability and grain security.

Species Investigation of Rice Stem Borers and Its Parasitoids on Fallowing Rice Fields at Karawang, Indonesia

<p>Rice stem borers (RSB) cause the same damage symptoms and occur through the season and time. During the off-season for rice, these stem borers are not well-known. The research aims to determine the effect of fallowing rice on the presence of rice stem borers and their parasitoids, the potential for RSB infestation, and their parasitoid on subsequent rice seedlings in nurseries at Karawang Regency, West Java. Several variables are observed, including the number of rice stem borer larvae on stubbles, egg masses, the percentage of parasitized eggs, and the number of adults of rice stem borer in nurseries. The results show that species of rice stem borer on the fallow rice are <em>Scirpophaga incertulas</em> and <em>Sesamia inferens</em>. The population of <em>S. incertulas</em> is significantly higher on long rice fallow. The height of the paddy stubble at the two locations is not very different. However, the infested stubble in the short fallow period is higher than those in the long fallow. Eggs of <em>S. incertulas</em> whose high percentage hatched and parasitized, are primarily found in nurseries of areas with long fallow. There are three species of parasitoids identified.</p>

The choice of rice rotation system affects the composition of the soil fungal community and functional traits

Plant rotation is a common practice in upland rice production. However, the effects of plant rotation on the interactions between rice plants, soil and underground ecosystems need to be studied further. Here, quantitative PCR and high-throughput pyrosequencing of the ITS region was applied to investigate the fungal abundance, diversity, and composition of fungal functional guilds in rice field soils and after different rotation practices ((rice-fallow (RF), rice-Chinese milk vetch (RV) and rice-wheat (RW)) and their relationship with rice yields. The results showed that the six-year RV and RW rotations increased fungal abundance by 42.7 %–69.2 % relative to RF, but decreased the soil bacterial-to-fungi ratio and fungal diversity. For the functional guilds, RV rotation significantly increased the relative abundance of soil saprotrophs and pathotrophs by 73.30 % and 32.94 %, respectively, while that of symbiotrophs was decreased by 35.96 %, compared to RF. RW rotation was found to significantly decrease all three fungal functional guilds, but increased the symbiotroph-saprotroph ratio. A structure equal model analysis indicated that the diversity of saprotrophs was significantly and negatively correlated with rice yield. Altogether, this work provides a detailed description of how the soil fungal community, including saprotrophic, symbiotrophic and pathotrophic functional guilds, responded to different upland rice rotation practices after eight years of application.

CROP ROTATIONAL EFFECTS ON INFESTATION OF STEM BORERS IN RICE

The present study investigates the impact of crop rotation on the infestation of stem borers in rice crops. This research was carried out in the field at Shaheed Zulfiqar Ali Bhutto Agricultural College Dokri, Sindh, Pakistan. Several rotation practices were tested, including Rice fallow Rice, Rice-Wheat-Rice, Rice-Gram-Rice, Rice-Barseem-Rice, and Rice-Mustard-Rice. The results of the study revealed interesting findings. The lowest infestation rate, approximately 1.92% of rice stem borers, was observed in the Rice-Barseem-Rice rotation. This was followed by Rice-Mustard-Rice at 2.18%, Rice-Gram-Rice at 2.40% and Rice-Wheat-Rice at 3.21%. In contrast, the highest infestation rate, reaching 4.99%, was recorded in the Rice-fallow-Rice rotation system. These findings suggest that incorporating winter rotation crops such as Mustard, Barseem, and Gram into the cropping system can significantly reduce the population density of rice stem borers. On the contrary, mono-cropping, as exemplified by the Rice-fallow-Rice rotation, appears to favor stem borer infestations. In light of these results, it is recommended that further research and understanding be developed to implement cultural control methods and ensure ecological safety within winter crop rotation systems. This study underscores the importance of diversified crop rotation practices in mitigating the infestation of harmful pests like rice stem borers, contributing to sustainable agriculture and higher crop yields.

Response of Spider and Epigaeic Beetle Assemblages to Overwinter Planting Regimes and Surrounding Landscape Compositions.

The rotation patterns of summer rice-winter oil seed rape and summer rice-winter fallow are the main planting regimes in the rice ecosystem in southern China. However, the impact of local rotation patterns and landscape factors on the overwintering conservation of predators in spider and epigaeic beetle assemblages remains poorly understood. Here, we investigate the diversity and density of spiders and beetles over two consecutive winters (2019/2020 and 2020/2021), focusing on the impact of two rotation patterns (rice-fallow and rice-oilseed rape) and surrounding landscape compositions on predator diversity. The main findings of our research were that spiders were more abundant and had a higher activity density in the fallow rice fields (FRs) compared to the oilseed rape fields (OSRs), whereas ground beetles exhibited the opposite pattern. Specifically, fallow rice fields supported small and ballooning spiders (e.g., dominant spider: Ummeliata insecticeps), while OSRs supported larger ground beetles (e.g., dominant beetles: Agonum chalcomus and Pterostichus liodactylus). Moreover, the composition of spider assemblages were impacted by semi-natural habitats (SNHs) during overwintering, while ground beetle assemblages were influenced by overwinter planting patterns. Overall, our results suggest that different planting regimes and preserving semi-natural habitats are a strategic way to enhance species diversity and functional diversity of ground predators. It is, therefore, recommended that to conserve and improve predator diversity during overwintering, land managers and farmers should aim to maintain diverse planting regimes and conserve local semi-natural habitats.

Varietal Performances and Foliar Application of Nutrients on Yield and Economics of Utera Rapeseed-Mustard in Rice-Fallow of Alluvial Soils

A field experiment was conducted during winter seasons (November to February) of 2020–21 and 2021–22 to evaluate performances of different rapeseed-mustard varieties under foliar spray of nutrients on growth, yield components, yield and economics of utera (relay) rapeseed-mustard grown in rice–fallow. The experiment was laid out in a split plot design keeping rapeseed-mustard varieties, viz., Anushka, Binoy and PM-28 in main plots and eight different foliar spray of nutrients in sub-plots. Variety PM 28 registered significantly higher growth attributes, yield components, seed yield (1198.5 kg ha-1), stover yield (3300.4 kg ha-1) and biological yield (4498.8 kg ha-1) and also achieved significantly higher return per rupee invested (`Rs. 2.05) over other two varieties. Foliar spray of N:P:K (19:19:19) @2% twice at 30 DAS and 45 DAS+ZnSO4 @ 0.05% at 40 DAS+Boron (20%) @ 0.1% at 50 DAS was found significantly superior to all other foliar sprays with respect to yield components and seed yield (1233.2 kg ha-1), stover yield (3109.9 kg ha-1) and biological yield (4343.2 kg ha-1) irrespective of the varieties and also gave significantly higher return per rupee invested (Rs. 1`.93) over other foliar application. The study revealed that, cultivation of rapeseed-mustard along with foliar application of nutrients in rice fallow of alluvial soils of West Bengal was a better option to enhance growth, productivity and economics of utera rapeseed-mustard.

Differences in Methanogenic Pathways and Communities in Paddy Soils Under Three Typical Cropping Modes

AbstractThe methane (CH4) production process in paddy fields varies depending on different cropping modes. However, there is limited knowledge on the changes in anaerobically produced CH4 isotopic ratios (δ13CH4), the methanogenic pathways, and the dominant communities of methanogens in paddy soils under different modes. To address this, we conducted experiments using anaerobic incubation methods, stable carbon isotope fractionation through inhibition studies with fluoromethane, and high‐throughput sequencing. These methods allowed us to measure the CH4 production potential (MPP), the relative contribution of acetoclastic methanogenesis to CH4 production (fac), and the composition of the methanogen community in paddy soils under three typical cropping modes: Rice‐Wheat (RW), Rice‐Fallow (RF), and Double‐Rice (DR) in China. The results showed that MPP was 30.7 μg CH4 g−1 d−1 in DR soil, around 57% and 66% higher than that in RW and RF soils, respectively, possibly due to the lower pH, clay content, and higher abundance of the mcrA gene. Moreover, RF soil had the highest value of produced δ13CH4 (−43.9‰) but the lowest value of produced δ13CO2 (−26.3‰). Based on the carbon isotope fractionation associated with methanogenesis via H2/CO2 reduction (1.049–1.062), the values of fac estimated in the RF soil (80%–98%) were much higher than that in the RW (39%–60%) and DR soils (52%–75%). This could be supported by the finding showing that Methanosarcina, the acetoclastic methanogens, were dominant in RF soil, while Methanosarcina and Methanobacterium (the hydrogenotrophic methanogens) dominated in RW and DR soils. Redundancy analysis revealed that the community structure of methanogens was significantly affected by soil pH. The findings suggest that differences in the abundance and composition of methanogens, possibly driven by soil pH, play a key role in regulating methanogenesis in the paddy soils, and further provide valuable insights into the process of CH4 production in different cropping modes.

Sesame (Sesamum indicum L.): A Potential Allelopathic Crop - A Review

Sesame (Sesamum indicum L.) is one the oldest oilseed crop cultivated in India. It is cultivated as third crop in summer rice fallows or in marginal lands. Seeds of sesame are used for the extraction of oil, that contain many pharmaceutical and cosmetic properties. Research findings revealed that sesame contains many allelochemicals. The present review focuses on the allelopathic effect of sesame on weeds and crops. Exploring the allelopathic potential of sesame would help to develop bio-herbicides in future and reduce the use of synthetic herbicides in weed management. In addition to this, study on allelopathy of sesame would help to select suitable crops in rotation which are compatible to the sesame.

Identification of suitable genotypes of lentil (Lens culinaris) for improved adaptation to rice fallow areas of Gangetic Alluvial Zone

Rice fallows (RF) are the low lying kharif sown rice (Oryza sativa L.) areas that remain uncropped due to dearth of suitable cultivars of winter (rabi) pulses. A panel of 30 promising high yielding lentil (Lens culinaris Medik.) genotypes of diverse origin were assessed at both no till RF and with till condition at the Regional Research Substation (RRSS), Chakdah under the aegis of Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal for two years (2019–20 and 2020–21). Multi-trait performance (earliness, biomass and grain yield) of each genotype was considered during recommendation of suitable genotype for specific ecology deploying GGE biplot. The presentstudy recommended IC 560183 for no till RF ecology and Moitree, IC 559996, ILL 7978 and L 1112-19 for with till ecology having specific adaptation. Additionally, 2011S-56212-2 and ILL 8006 were identified as ideal and desirable genotypes for both the ecologies and therefore, recommended for commercial cultivation across the areas of Gangetic alluvial zone for augmenting lentil production and productivity.

Influence of Super Nano Urea and Nano DAP on Growth Parameters of Rice Fallow Cotton under High Density Planting System

The experiment was carried out at wetlands farm, Tamil Nadu Agricultural University, Coimbatore, during summer, 2023 in a Randomized block design with ten treatments and replicated thrice. The main objective of this study is to find out the effect of varied dose of basal nitrogen & phosphorus and foliar application of conventional urea, super nano urea and nano DAP on rice fallow cotton under High Density Planting System (HDPS) on growth parameters. Cotton variety CO 17 was taken up for the study with RDF of 150:50:50 NPK Kg ha-1. The experimental details viz., T1- control (without N&P) K alone, T2- RDF (150:50:50 NPK Kg ha-1), T3- 50% RDN&P,100% K+ conventional urea @ 1% and nano DAP @ 0.5% at 25 DAS, T4- 50% RDN&P,100% K+ conventional urea @ 1% and nano DAP @ 0.5% at 25 DAS and 45 DAS, T5- 50% RDN&P,100% K+ SNU(Super Nano Urea) @ 0.25% and nano DAP @ 0.5% at 25 DAS (Days After Sowing) and 45 DAS, T6- 50% RDN&P,100% K+ SNU @ 0.25% and nano DAP @ 0.5% at 25 DAS, 45 DAS and 65 DAS, T7- 50% RDN&P,100% K+ SNU @ 0.5% and nano DAP @ 0.5% at 25 DAS and 45 DAS, T8- 25% RDN&P,100% K+ SNU @ 0.5% and nano DAP @ 0.5% at 25 DAS 45 DAS and 65 DAS, T9- 50% RDN&P,100% K+ SNU @ 1% and nano DAP @ 0.5% at 25 DAS, T10- 50% RDN&P,100% K+ SNU @ 1% and nano DAP @ 0.5% at 25 DAS and 45 DAS. The experimental results revealed that, among all the treatments, T10 significantly registered the increased plant height (112.33 cm) and highest leaf area index (4.11) and enhanced light interception (91%). Based on the experimental results, it is concluded T10 i.e., reduced application of basal nitrogen and phosphorus (50% RDN&P + 100% K) with super nano urea foliar spray @ 1% and nano DAP foliar spray @ 0.5% at 25 DAS and 45 DAS found to be the optimal dosage for increased growth parameters under high density planting system in rice fallow cotton.