Resource utilization and sustainability of conservation-based rice-wheat cropping systems in Central Asia

Excessive and inefficient water use, intensive soil tillage and decreasing soil fertility have caused land degradation and desertification, which are threatening the sustainability of rice-wheat systems in the irrigated lowlands of Central Asia. Water-saving and conservation agriculture (CA) practices such as alternate wet and dry irrigation (WAD), direct seeding on raised beds, zero tillage flat lands, and residue retention can help counterbalancing these threats. A randomized complete block design experiment with four replications was conducted from 2008-2010 in rice-wheat rotation systems in Khorezm region, Uzbekistan. Objectives were to (1) investigate the growth and yield formation of rice, (2) examine mineral-nitrogen (N) dynamics in a rice-wheat system, and (3) evaluate the sustainability of a rice-wheat system under water-saving irrigation and CA practices. Next, the rice growth model ORYZA2000 was parameterized and evaluated to assess the impact of increased temperature on phenology and grain yield of rice at various emergence dates under IPCC (2007) projected A1F1 and B1 climate change scenarios. The rice variety used was a puddle rice variety subjected to dryland conditions. The field experiment centered on six WAD rice treatments involving dry-direct seeded rice (DSR) under raised bed planting (BP) and zero tillage (ZT) planting on flat land combined with three levels of residue retention, i.e., residue harvested (RH), 50% residue retention (R50), and 100% residue retention (R100). These were compared with wet-DSR grown under conventional tillage (CT) with continuous flood irrigation (CT-FI) and with intermittent irrigation (CT-II). The WAD and CT-II treatments were irrigated only when the soil water potential in the top 20 cm soil reached around -20 kPa. CT-FI was irrigated as practiced by the farmers in the region. Wheat was surface seeded into the standing rice field in all treatments. To assess the impact of climate change with ORYZA2000, field experiments with six seeding dates and three varieties were conducted in 2008-2009. WAD irrigation led to a 68-73% water-saving potential but reduced rice yield by 30-56%; however, the yield of surface seeded wheat was higher by more than 1.5 t ha-1 than the irrigated wheat yield in Khorezm in both years. With WAD, this yield penalty was caused by water stress, higher amount of standing residue retention, and N stress, which reduced biomass accumulation and root growth, delayed phenological development, reduced number of spikelets, and led to a high percentage of unfilled grains. WAD plus residue retention (R50 and R100) in rice led to N losses. Combined over two seasons of rice and one season of wheat, the N loss was highest (>350 kg ha-1) with R100 and lowest with CT-FI (261 kg ha-1) and could have been caused by leaching and denitrification. No mineral N was lost in any of the wheat treatments. Rice-wheat system productivity, gross margin, and benefit to cost (B:C) ratio were highest in CT-FI followed by RH, and lowest with R100 in BP and ZT. The discharge of irrigation water through seepage and percolation from the rice fields amounted to about 90% with CT. Yields can be increased with water-saving under CA practices with proper residue management, optimization of irrigation, N drilling (nitrogen placement 5-10 cm deep into the soil), strip-till transplanting (seed/seedling placement in a shallow-tilled strip), and the use of suitable aerobic rice varieties. With the present anaerobic varieties used under aerobic conditions, yield penalties are discouraging despite the high savings in water use. As long as farmers do not pay for irrigation water, the incentives may be insufficient to provoke any change. The parameterized ORYZA2000 simulated phenology and grain yield of rice with a high accuracy (RMSE-1 or 393 kg ha-1°C-1) in 2079 compared to 2000. Under current conditions, the best seeding dates are ~July 5 for short-, ~June 15 for medium-, and ~ June 5 for long-duration rice varieties (varieties maturing in 110 days, respectively). Seeding dates were not changed under the B1 climate change scenario but could be delayed by 10 days under the A1F1 scenario. Development of heat-tolerant, medium- and long-duration rice varieties is crucial under climate change scenarios.Ressourcenutzung und Nachhaltigkeit von bodenschonenden Reis-Weizen-Anbausystemen in Zentralasien Exzessive und ineffiziente Wassernutzung, intensive Bodenbearbeitung sowie abnehmende Bodenfruchtbarkeit haben zu Landdegradation und Wüstenbildung geführt. Dies bedroht die Nachhaltigkeit der Reis-Weizensysteme der bewässerten Tieflandregionen in Zentralasien. Wassersparende Bewässerung und konservierende Bodenbearbeitung (CA) mit, zum Beispiel, alternierender Bewässerung (WAD), direkter Aussaat auf erhöhtem Pflanzbett (BP), pflugfreier Anbau (ZT), und Belassen der Ernterückstände auf dem Feld können den obengenannten negativen Auswirkungen entgegenwirken. Eine Versuch unter randomized complete block design mit vier Wiederholungen wurde 2008-2010 in Reis-Weizen-Rotationssystemen in der Region Khorezm, Usbekistan, durchgeführt. Das Ziel war, folgendes zu bestimmen: (1) Wachstum und Ertragsbildung von Reis, (2) mineralische Stickstoff-(N)-Dynamik in einem Reis-Weizensystem, und (3) Nachhaltigkeit eines Reis-Weizensystems bei wassersparender Bewässerung und CA. Als nächstes wurde das Reiswachstumsmodell ORYZA2000 parameterisiert und evaluatiert, um die Auswirkungen gestiegener Temperaturen auf Reisphänologie und -ertrag bei verschiedenen Keimungsterminen unter den A1F1 und B1 Klimawandelszenarien (IPCC 2007) zu ermitteln. Der eingesetzte Reis war eine Nassreissorte, die unter trockenen Bedingungen verwendet wurde. Der Feldversuch umfasste sechs WAD Reisbehandlungen mit Trocken-Direktaussaat (DSR) mit Bettbepflanzung (BP) und Anbau ohne Bodenbearbeitung (ZT) kombiniert mit drei unterschiedlichen Behandlungen mit Ernterückständen, d.h., vollständig geerntete Rückstände (RH), Belassen von 50% der Rückstände (R50), und Belassen von 100% der Rückstände (R100). Die Ergebnisse wurden mit denen von Nass-DSR mit konventioneller Bodenbearbeitung (CT), mit Dauerbewässerung (CT-FI) sowie mit intermittierender Bewässerung (CT-II) verglichen. Die WAD- und CT-II-Behandlungen wurden nur bewässert wenn das Bodenwasserpotenzial in den oberen 20 cm des Bodens ca. -20 kPa erreichte. CT-FI wurde so bewässert, wie es bei den Bauern in der Region üblich ist. Der Weizen wurde in allen Behandlungen oberflächlich zwischen den Reispflanzen ausgesät. Um die Auswirkungen des Klimawandels mit ORYZA2000 zu ermitteln, wurden Feldversuche mit sechs Aussaatterminen in 2008 und 2009 durchgeführt. Die WAD Bewässerung führte zu einem 68-73%igen Wassersparpotenzial, jedoch war der Reisertrag bis zu 30-56% geringer. Der Ertrag des oberflächlich ausgesäten Weizens war jedoch 1.5 t ha-1 höher als der Ertrag des bewässerten Weizens in der Khorezm-Region in beiden Jahren. Gründe für den geringeren Reisertrag bei WAD waren Wasserstress, höhere Mengen von Ernterückständen sowie N-Stress. Diese Faktoren führten zu einer Abnahme von Biomassenbildung und Wurzelwachstum, Verzögerung der phänologischen Entwicklung, einer geringeren Anzahl von Ährchen und einem hohen Prozentsatz leerer Körner. WAD zusammen mit Ernterückständen (R50 und R100) führte bei Reis zu N-Verlusten. Kombiniert über zwei Anbauperioden von Reis und eine von Weizen war der N-Verlust am höchsten mit R100 (>350 kg ha-1) und am niedrigsten mit CT-FI (261 kg ha-1). Gründe könnten Auswaschung oder Denitrifikation gewesen sein. In keinem der Versuche mit Weizen wurden Verluste von mineralischem N beobachtet. Im Reis-Weizensystem waren Produktivität, Bruttoergebnis und Aufwand-Nutzen-Quotient am höchsten in CT-FI, gefolgt von RH, und am niedrigsten in den R100-Behandlungen in BP und ZT. Der Verlust von Bewässerungswasser in den Reisfeldern durch Versickerung und Perkolation betrug ca. 90% bei CT. Bei CA können höhere Erträge bei wassersparenden Maßnahmen mit entsprechender Nutzung der Ernterückstände, Optimierung der Bewässerung, Applikation von N in 5-10 cm Bodentiefe, Streifenlockerung und Pflanzung der Reissetzlinge, und Nutzung geeigneter aerober Reissorten erzielt werden. Wenn anaerobe Reissorten unter aeroben Bedingungen eingesetzt werden, sind die geringeren Erträge entmutigend trotz der hohen Wassereinsparungen. Solange die Bauern nicht für das Wasser bezahlen, ist es unwahrscheinlich, dass sie wassersparende Maßnahmen einsetzen werden. Das parameterisierte ORYZA2000 simulierte Reisphänologie und -körnerertrag mit hoher Genauigkeit (RMSE-1 bzw. 393 kg ha-1 °C-1) in 2079 im Vergleich zu 2000. Unter den bestehenden Bedingungen sind die besten Saattermine um den 5. Juli für die Kurz-, um den 15. Juni für Mittel-, und um den 5. Juni für Langzeit–Reissorten (welche, respektive, in >100, 100-110, und >110 Tagen reifen). Aussaattermine könnten unter dem B1-Szenario unverändert bleiben, während sie unter dem A1F1-Szenario 10 Tage später sein könnten. Die Entwicklung von hitzetoleranten, Mittel- und Langzeit-Reissorten ist entscheidend bei den vorhergesagten Szenarien des Klimawandels

Learning Chemistry through Interactive Demonstration: A Pedagogical Perspective

This study was carried out to determine the achievement of school students in learning chemistry. Based on a quasi-experimental research strategy, this study looks at chemistry education at the secondary level. We chose three purposively selected public schools and six selected science teachers from those schools. A simple random sample was used to pick 120 students (57 females and 63 males). Generated data from CAT and CAS were examined manually and with IBM SPSS version -21. Pre-test results showed no significant differences in student performance by group or gender. Students in the experimental group performed well on the post-test, indicating that the interactive demonstration approach effectively taught chemistry. There was no need for students to act differently based on their gender, and they were all very supportive of each other's academic success. Most pupils struggle with understanding the concept of a chemical reaction. Overall, this study's findings imply that interactive demonstration substantially impacts student achievement and that gender does not play a role in student success. Thus, the interactive demonstration method (IDM) is advocated for use in the classroom to help students learn and understand the types of chemistry they will experience in their daily lives

Vancomycin Intermediate MRSA Isolates Obtained from Retail Chicken Meat and Eggs Collected at Pokhara, Nepal

Antimicrobial resistance among food animal isolates is increasing as a result of their uncontrolled uses. The monitoring of antibiotic resistance among these isolates is very necessary. S aureus was isolated from eggshells and chicken meat samples collected from different retail outlets of the Pokhara metropolitan. Samples were inoculated on Mannitol salt agar aseptically and inoculated overnight. Isolated yellow colonies were further examined by Gram-staining, catalase, and coagulase test to detect S aureus. Methicillin resistance was screened using cefoxitin disc. Vancomycin minimum inhibitory concentration (MIC) of Methicillin-resistant S aureus (MRSA) isolates were determined by the agar dilution method following CLSI guidelines. 139 S aureus were isolated from 205 samples. Among them, 89 were from egg samples (out of 125 samples) and 50 from chicken (out of 80 samples). The overall prevalence of MRSA was 12.94%. Antibiotic resistance was significantly higher in MRSA isolates compared to Methicillin sensitive S aureus (MSSA) isolates. The highest rate of resistance was noted for ampicillin, amoxicillin, and erythromycin while the least resistance was noted for gentamicin and amikacin. Vancomycin minimum inhibitory concentration (MIC) range of the MRSA isolates was 0.25-8μg/ml indicating the detection of both vancomycin-intermediate and sensitive isolates from the samples. This is the first study reporting vancomycin-intermediate S aureus (VISA) isolates from Nepal and indicates the increasing drug resistance among animal isolates. Further surveillance studies about the transmission of these pathogens to humans as well as detail molecular analyses are imminent

Minimum Dataset Required to Collect from Agronomic Field Experimentation

Implementing strategic field experimentation not only provide opportunities to solve the research questions but also provide a useful way to address a number of important issues in crop, soil, water, environmental and resource economics using different analytical tools. As implementing field experimentation is resource intensive (cost, time and energy), it is important to plan for collecting/generating standard data set (both quality and minimum number)

Conservation agriculture improves agronomic, economic, and soil fertility indicators for a clay soil in a rainfed Mediterranean climate in Morocco

CONTEXT: Declining rainfall with increasing variability, increasing temperature extremes, and declining soil fertility are threatening crop production and ultimately food security in the rainfed Mediterranean environment in Morocco. Conservation agriculture (CA) practices such as reduced tillage, soil cover, and appropriate crop rotation are recognized as a set of adaptive agricultural systems in such climate-sensitive regions. Systematic evaluation of agronomic, economic, and soil fertility indicators with medium-and long-term adoption of CA in different crop rotations in such variable climatic conditions is needed to drive wider adoption of CA in the region. OBJECTIVE: The objective of this study was to systematically evaluate agronomic, economic, and soil fertility indicators under CA and conventional tillage (CT) using field experimentation (medium-term) and simulation modeling (long-term) for a clay soil of a rainfed Mediterranean environment. METHODS: Methodologies included the following: 1) Field experimentation for 5 years (2015–2019), comparing CA and CT in four major food crops: wheat, barley, lentil, and chickpea, conducted in Merchouch, Morocco. The objective was to determine the effect of CA on crop productivity, yield stability, profitability, precipitation use efficiency, and soil fertility indicators of individual crops and cropping systems. (2) Dynamic simulation modeling to understand the long-term effect of adopting CA and CT under cereal–legume and cereal–cereal rotation systems. Using 5 years of experimental data, we calibrated and validated a Decision Support System for Agrotechnology Transfer (DSSAT) model for four crops; and ran the model for 36 years for two major rotations

Gender Dimensions of Food Security, the Right to Food and Food Sovereignty in Nepal

The right to food is the right to life. Ensuring food security for all the citizens and their food sovereignty is the responsibility of the State. Currently, the need for food security, especially for marginalized and oppressed sections of society, including women in Nepal, is inadequately addressed. In this context, the main objective of this paper is to examine the gender dimensions in food policies and programs in Nepal. The paper explores five dimensions of food security, the right to food and food sovereignty, and analyzes gender inclusivity in food policies and governance in particular, since the advent of the sixth periodic plan (1980-1984) that included gender issues for the first time in the planning history. The paper, employing qualitative methods, recognizes that ensuring food governance is not only essential for equitable food security and the right to food, but also to the process of transforming discriminatory cultural norms and values into equitable ones and strengthening the psychological well-being of women. This paper argues that exclusion of women from decision-making processes leads to their psychological disempowerment. Women’s participation in socio-cultural, economic, and political spheres directly impacts processes to identify and recognize their needs, preferences and priorities in food policies and programs. The article concludes, that since food security and the right to food impact women and men differently, a transformational process must respond to gender-differentiated interests, choices, preferences and entitlements. This paper proposes a framework to promote gender responsive food systems and concludes that gender responsive food policies, programs, institutional arrangements and behavioral change of individuals, families and communities are crucial to ensure the right to food for all

Managing salinity for sustainable agricultural production in salt-affected soils of irrigated drylands

CONTEXT Declining water quantity and quality and poor land, water, and crop management practices are leading to increasing soil salinity, land degradation, desertification, and threatening the overall sustainability of the crop production system in irrigated drylands. Assessments of salinity dynamics and sustainability indicators under alternative agricultural practices are needed to identify the right combination of practices that improve sustainability while minimizing land and environmental degradation. OBJECTIVE The objective of this study was to assess the potential of conservation agriculture (CA)-based practices, water-saving irrigation, water quality, and nitrogen (N) fertilizer rates for improving the sustainability of rice-wheat (RWS) and cotton-wheat (CWS) systems in salt-affected irrigated drylands. METHODS The study included mixed-method approaches of two years of field experiments, soil profile and groundwater salinity simulation using Hydrus-1D model, and multi-criteria trade-off analysis for the holistic assessment of alternative innovations in RWS and CWS. The treatments in experiments were composed of a combination of CA-based practices, water-saving irrigation and N rates. Fourteen sustainability indicators computed from experiments and simulation were compared to evaluate the sustainability of those cropping systems and to reveal the potential of those practices for improving sustainability. RESULTS AND CONCLUSIONS Compared to the initial conditions, the soil salinity decreased in both cropping systems, while the reduction rate was much higher in RWS than CWS (by 28%). In RWS, the conventional treatment had the lowest salinity level, while in CWS, CA (permeant bed + residue retention) had the lowest. RWS raised the groundwater table by 25% compared to CWS. The long-term scenario analysis with Hydrus-1D demonstrated that, with increased irrigation water salinity and soil evaporation rates, soil profile salinity increases by 78% in RWS and 66% in CWS. RWS had a higher net profit (+81%) and soil organic carbon (SOC) (-15%), but lower water productivity (WP) (−147%), nitrogen, and energy use efficiency (EUE) (−46%) than CWS. The CA-based practices in CWS improved sustainability indicators with higher yield and net profit (+20%), WP (+26%), SOC (+456%), and EUE (36%) with decreased soil salinity than in the conventional system

Potential of Crop Simulation Models to Increase Food and Nutrition Security Under a Changing Climate in Nepal

With current trends of increasing population, decreasing arable land, and a low yearly increment rate of cereal productivity, Nepal has an annual deficit of >1.3 million tons of edible rice, wheat, and maize. This indicates the urgent need for demand-led agricultural interventions for improving cereals productivity for food security. Crop simulation models and DSS tools have potential to predict potential yields, identify yield gaps, and help make decisions for improved crop, nutrient, water and pest management. Models can assess the impact of climate change, and help develop adaptation and mitigation measures to lesses the impact of climate change. To date, no review work has been conducted on the potential applications of crop simulation models and their relevance in Nepal. The objective of this chapter is to review and synthesize the relevant studies on the development and application of crop simulation models for major cereal crops: rice, wheat, and maize. We reviewed around 95 published papers and reports from South Asia and Nepal available in Scopus, SpringerLink, and ScienceDirect using the Google search engine. Analysis revealed that yield gaps (potential minus farmers' field yields) of 4.9–9.0, 3.1–6.9, and 4.5–12.5 t ha−1 exist in rice, wheat, and maize crops, respectively. For achieving self-sufficiency in cereal grains, the average national productivity of rice, wheat, and maize needs to be increased to 5.7, 3.9, and 4.9 t ha−1, respectively by 2030. Based on the review, climate change has both positive and negative consequences on cereal production across all agro-ecological zones. Crop simulation models have been applied for enhancing crop productivity and exploring adaptation strategies for climate change resilience. Models can generate various recommendations related to biophysical factors: crop, water, tillage, nutrient, and pest management, crop yield, and weather forecasting. Furthermore, models have shown the potential to determine the effects of climate change on crop productivity across a range of environments in Nepal. In conclusion, crop simulation models could be useful decision support tools for policy planning and implementation, increasing efficiency in research, prioritizing research and extension interventions for increasing crop yields, and the way forward to achieve food and nutritional security and some of the Sustainable Development Goals (particularly #1, #2 and #13)

Issues in rice marketing system: a case of central terai

This study was conducted to understand the challenges and prospects of ricemarketing by taking case of central Nepal. Two focus group discussionsalong with eight key informants’ interviewswere conductedinBara and Parsa districts of Nepal.Also, secondary information was collected by reviewing the related literatures.The study revealed that the consumer price of rice is almost double than the farm gate price, possibly due to the presence of several intermediaries in different nodes of the supply chain.Key market actors like large collectors, millers and wholesalers have a dominating role in price negotiation and supply of rice in the market. The rice value chain is not strong enough, which might be due to poor vertical and horizontal as well as backward and forward linkages among the key players. The demand of fine and aromatic rice is gradually increasing due to changing food habits of the consumers and their access to purchasing capacity as well.The high yielding short duration varieties of fine and aromatic rice need to be identified and developed to meet the growing demand of consumers.In addition, to boost productivity and profitability of rice, a better investment climate, risk sharing mechanism and strengthened value chain with efficient research and extension services are required

Antibiotic Susceptibility Profile of respiratory pathogens obtained at tertiary care hospital from western Nepal

The prevalence and drug resistance of the respiratory pathogens is increasing gradually in Nepal. However, their detail study is rare in the western region of Nepal. Hence, this study was carried out to know the incidence and antibiotic susceptibility profile of the respiratory pathogens obtained at a tertiary care center located at Pokhara. 139 pathogens were isolated from 460 clinical samples included. Significant pathogens were Gram-negative bacteria 94 (67.62%), followed by 28 (20.15%) Candida, and Gram-positive isolates 17 (12.23%). The growth rate was significantly higher for sputum samples in comparison to throat swabs. Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter were significant Gram-negative isolates while Staphylococcus aureus, Streptococcus pneumoniae, and Streptococcus pyogenes were Gram-positive pathogens. Sensitivity rate was higher for colistin and imipenem among Gram-negative isolates while lower sensitivity was for cefepime. Vancomycin was effective against all tested Gram-positive isolates while erythromycin and ciprofloxacin were less effective