Coastal Zone Of Bangladesh Research Articles

Fall armyworm (S. frugiperda) an Emerging Risk for the Expansion of Maize in the Coastal Zone of Bangladesh: A Survey of Farmers’ Perception and Practices

Fall armyworm (S. frugiperda) an Emerging Risk for the Expansion of Maize in the Coastal Zone of Bangladesh: A Survey of Farmers’ Perception and Practices

Vulnerability assessment of tropical cyclones and deep depressions: an index-based spatio-temporal assessment along the coastal zones of Bangladesh

Vulnerability assessment of tropical cyclones and deep depressions: an index-based spatio-temporal assessment along the coastal zones of Bangladesh

Effect of plant growth regulators on growth, yield and yield contributing characters of brinjal (Solanum melongena L.) in coastal zone of Bangladesh

Salinity is a serious environmental issue that reduces the yield of vegetable crops. Brinjal is one of the world's most popular vegetable crops and its productivity and quality are heavily influenced by the salt content in the root area. Plant growth regulator management, however, is a key factor that can be used to increase brinjal production in moderate saline soils. The experiment was carried out at the Agricultural Research Field, Noakhali Science and Technology University, Noakhali, Bangladesh during the period from January to June 2022, to observe the effect of plant growth regulators on growth, yield, and yield contributing characters of brinjal (Solanum melongena L. V: Purple king ). The experiment was followed Randomized Complete Block Design (RCBD) comprising four treatments with three replications. The treatments were T0 (Control), T1 (Salicylic acid @ 60 ppm), T2 (Gibberellic acid @ 60 ppm), T3 (Naphthalene acetic acid @ 60 ppm). Data were recorded from different stages of plant growth viz, plant height, number of leaves per plant, number of branches per plant, number of fruits per plant, fruit length, fruit diameter, fruit weight, and yield. The maximum plant height (100.00 cm), number of leaves per plant (197.17) , number of branches per plant (17.17), number of flowers per plant (62.67), number of fruits per plant (34.42), fruit length (25.50 cm), fruit diameter (3.33 cm), weight of fruit (92.67 g), yield per hectare (22.17 t ha-1) were measured from treatment T2 (GA3 @ 60 ppm). Results conclude that the application of gibberellic acid @ 60 ppm for brinjal cultivation gave better growth and yield in moderate saline soils. Res. Agric. Livest. Fish. Vol. 10, No. 2, August 2023: 91-97

Mainstreaming Decentralization and Collaboration in Disaster Risk Management: Insights from Coastal Bangladesh

Bangladesh is renowned in disaster risk reduction (DRR) for active involvement of community people and local disaster management institutions in DRR activities. Our study aimed to describe the disaster risk management (DRM) institutions and assess their functioning in six coastal unions across the three coastal zones of Bangladesh. Both qualitative and quantitative research approaches were used. The study focused on two key local institutions—the Union Disaster Management Committees (UDMCs) and the Cyclone Preparedness Program (CPP)—functioning at the union level in DRM. Such institutions have both horizontal and vertical collaborations with other institutions. However, we argue that the UDMCs’ external dependencies in their functioning indicate their limited financial and administrative autonomy, which is a barrier to successfully institutionalizing disaster management. The results show that the CPP is the most successful program, markedly increasing the trust of the people in warning dissemination and evacuation efforts in the event of a cyclone. Although the adoption of decentralized risk management systems has resulted in significant progress in increased rate of evacuation and reduced death rate and damage, lack of funding and equipment, limited coordination between institutions, lack of skilled and knowledgeable workforce, and inappropriate power structures may reduce the effectiveness of DRR activities prior to, during, and following disasters.

Monitoring of drainage system and waterlogging area in the human-induced Ganges-Brahmaputra tidal delta plain of Bangladesh using MNDWI index

Waterlogging is one of the major global problems which affects agro-economic activities around the world. In the coastal areas of Bangladesh, especially the southwestern coast, drainage congestion and waterlogging are very common which makes the area uninhabitable. Therefore, timely checking of drainage systems and surface water, and conveying data on the dynamics of drainages and surface water are important for plan and supervisory processes. The present study took an effort to illustrate the waterlogging and morphological change of the rivers in the southwestern coast of Bangladesh through the Modification Normalized Difference Water Index (MNDWI) values which are valuable indicators for monitoring the water area and land use pattern change. Landsat images (Landsat L8 Oli TIRS, Landsat ETM+, Landsat TM) were used in the research. The study reveals that from 1989 to 2020, the shallow water area (mostly covered with rivers) decreased by ∼14.30 km2 yr−1, whereas the wet-land area (mostly covered with beels and water logging areas) increased by ∼ 67.12 km2 yr−1. The bare land area also increased at a rate of ∼ 36.90 km2 yr−1. On the other hand, the green vegetation decreased at a rate of ∼166.1 km2 yr−1, whereas the moderate green vegetation area increased by ∼ 69.77 km2 yr−1 for the same period. In the coastal zones of Bangladesh, the polders, embankments, upstream dams, etc., enhance more sedimentation within the channels rather than in the nearby tidal plains. As a result, the shallow water area which is mostly covered by rivers is gradually decreasing. Moreover, due to increase in wet-land areas with salinity intrusions which affect the vegetation. Therefore, the green vegetation area is regularly declining due to demolition or conversion to moderate green vegetation. The findings of the research will be supportive for coastal scientists worldwide, policy makers & planners, and finally supportive for sustainable management of the coastal areas including Bangladesh.

Effect of nitrogen, phosphorus and potassium on the growth and yield performance of garlic (Allium sativum L.) in coastal zone of Bangladesh

The experiment was carried out at Agricultural Research Field, Noakhali Science and Technology University, Noakhali, Bangladesh during the period from November 2021 to March 2022, to observe the effect of nitrogen (N), phosphorus (P) and potassium (k) fertilizer on growth and yield of garlic (Allium sativum L. V: BINA Roshun-1). The experiment was laid out in a Randomized Complete Block Design (RCBD) comprising four treatments with three replications. The treatments were T0 (no NPK), T1 (NPK 70-70-100 kg ha-1), T2 (NPK 100-100-140 kg ha-1), T3 (NPK 130-130-180 kg ha-1), and here, N = Nitrogen, P=P2O5, K= K2O respectively. Data were recorded from harvesting stages of plant growth on the plant height, number of leaves per plant, leaf length, number of roots per plant, bulb diameter, bulb length, number of cloves per plant, whole weight of plant, fresh weight of bulb and fresh bulb yield per hectare. All the recorded parameters were statistically significant (p<0.01). The highest plant height (69.57 cm) was recorded from T3 (NPK 130-130-180 kg ha-1) whereas the lowest plant height (51.40 cm) was obtained from the control T0 (no NPK). The maximum number of leaves per plant (9.97), leaf length (38.10 cm), number of roots per plant (90.83), bulb length (3.30 cm), bulb diameter (3.80 cm), number of cloves per plant (28.97), whole weight of plant (65.07 g), fresh weight of bulb (42.50 g) and fresh bulb yield per hectare (2.83 t/ha) was found in treatment T3 (NPK 130-130-180 kg ha-1) whereas lowest data recorded from control T0 (no NPK). Observing the results, it can be stated that application of NPK fertilizer @ N 130 kg ha-1, P2O5 130 kg ha-1 and K2O 180 kg ha-1 for garlic cultivation gave better growth and yield in the coastal zone of Bangladesh. Res. Agric. Livest. Fish. 10(1): 53-60

Groundwater quality assessment and health issues in coastal zone of Bangladesh

The purpose of this study was to assess the water quality index (WQI), heavy metal evaluation index (HEI), heavy metal pollution index (HPI) and hazard index (HI), and the associated environmental/human health issues of the south-western coastal Bangladesh (SWCB). Rajoir, Gangarampur and Ganapatipur villages were purposively selected from shoreline (X), interim (Y) and inland (Z) coast of SWCB. 40 ground water samples were collected from 20 sampling sites; and 18 variables, such as, temperature, pH, electrical conductivity (EC), dissolved solids (TDS), suspended solids, dissolve oxygen, total hardness, Cl, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb ions were tested to perform the study. In addition, four focus group discussions were also conducted to understand the current health scenarios. The strong positive correlation between EC:Cu (r = 0.856), TDS:Mn (r = 0.664), TDS:Cu (r = 0.880), K:Mn (0.736) and Mn:Cu (r = 0.601) suggested the homogeneous sources of origin or/and anthropogenic activities or pollutant movement of these variables. The changing patterns of mean WQI, HEI, HPI, HIinfant, HIchild and HIadult of the study area were X(79.19)<Y(91.54)<Z(102.31); X(4.96)>Y(4.93)>Z(3.79); X(78.66)<Y(91.72)<Z(102.11); X(0.8)<Y(1.11)<Z(1.32); X(1.77)<Y(2.46) <Z(2.93); X(1.15)<Y(1.60)<Z(1.91), respectively. Therefore, it is argued that 66.67, 50 and 50% water samples from X, Y and Z coast grouped into category ‘very poor’, ‘excellent’ and ‘unfit’ based on WQI. In addition, 50, 40 and 50% water samples from X, Y and Z coast grouped into category ‘slightly affected’, ‘seriously affected’ and ‘moderately affected’ depending upon HEI. 100, 70 and 50% water samples from these villages were within the HPI (<100). Finally, the degree of pollution was increased from shoreline to inland areas based on HI results for infant, child and adult, respectively. Lastly, it confirmed that human health should be deteriorated for the long-term consumption of polluted/contaminated water and negatively impacted on biodiversity loss of the study area.

High-resolution synthetic population mapping for quantifying disparities in disaster impacts: An application in the Bangladesh Coastal Zone

The impacts of natural disasters are often disproportionally borne by poor or otherwise marginalized groups. However, while disaster risk modelling studies have made progress in quantifying the exposure of populations, limited advances have been made in determining the socioeconomic characteristics of these exposed populations. Here, we generate synthetic structural and socioeconomic microdata for around 9.5 million persons for six districts in Bangladesh as vector points using a combination of spatial microsimulation techniques and dasymetric modelling. We overlay the dataset with satellite-derived flood extents of Cyclone Fani, affecting the region in 2019, quantifying the number of exposed households, their socioeconomic characteristics, and the exposure bias of certain household variables. We demonstrate how combining various modelling techniques could provide novel insights into the exposure of poor and vulnerable groups, which could help inform the emergency response after extreme events as well targeting adaptation options to those most in need of them.

Harmful algal blooms in the coastal waters of Bangladesh: an overview

Harmful algal blooms (HABs) constitute a global problem, affecting aquatic ecosystems, human health, fisheries and local economies. The Bay of Bengal, along the Bangladesh coast, is exceedingly suffering from pollution or anthropogenic nutrification that influences frequently occurring HAB species. The progression of climate change and eutrophication invigorate HAB trends and responses that in turn affect the respective coastal livelihood and economic growth. Tripos spp., Dinophysis spp., Protoperidinium spp., Chaetoceros spp., and Pseudo-nitzschia spp. are the common bloom-forming HAB species in the coastal waters of Bangladesh. Despite having huge potentiality for regional and global perspectives, the coastal region of Bangladesh remains relatively unexplored compared to other regions in the context of HABs and their pernicious effects. As a result, harmful algal blooms and the accumulation of algal toxins may interrupt fisheries, aquaculture, aquatic ecosystems and public health in the country. Therefore, proper research on the biology and ecology of harmful algae, biotoxins and their relationship with environmental factors need to be adequately understood to minimize their adverse effects on the noted marine resources of the Bay. This review focused on an overview of the HAB related issues – causes of HABs, their occurrences and abundances, associated environmental factors and adverse effects in the coastal zone of Bangladesh.

Different morphs of Umbonium vestiarium (Gastropod) from the Bay of Bengal, Bangladesh coastal zone

As ecologically and economically, marine gastropod mollusca are highly significant in the benthic ecosystems. Among marine gastropods, Umbonium vestiarium (Linnaeus, 1758) is a key stone species in marine ecosystems. Adult Umbonium vestiarium from coastal areas in Bangladesh including Cox’s Bazar, Sonadia and the St. Martin’s Islands typically range from 1-2 cm, and exhibit extensive colour polymorphism.

A comprehensive review of heavy metal pollution in the coastal areas of Bangladesh: abundance, bioaccumulation, health implications, and challenges.

The coastal zone of Bangladesh, with a population density of 1278 people per square kilometer, is under serious threat due to heavy metal pollution. To date, many studies have been conducted on the heavy metal contamination in soils, water, aquatic animals, and plants in the coastal zone of Bangladesh; however, the available information is dispersed. In this study, previous findings on the contamination levels, distributions, risks, and sources of heavy metals in sediments and organisms were summarized for the first time to present the overall status of heavy metal pollution along coastal regions. Earlier research found that the concentrations of various heavy metals(HMs), particularly Co, Cd, Pb, Cu, Cr, Mn, Fe, and Ni in water, sediment, and fish in most coastal locations, were above their permissible limits. High concentrations of HMs were observed in sediments and water, like Cr of 55mg/kg and 86.93mg/l in the ship-breaking areas and Karnaphuli River, respectively, in coastal regions of Bangladesh. Heavy metals severely contaminated the Karnaphuli River estuary and ship-breaking area on the Sitakundu coast, where sediments were the ultimate sink of high concentrations of metals. Sedentary or bottom-dwelling organisms like gastropods and shrimp had higher levels of heavy metals than other organisms. As a result, the modified PRISMA review method was used to look at the critical research gap about heavy metal pollution in Bangladesh's coastal areas by analyzing the current research trends and bottlenecks.

Impact of Non-DRR NGOs’ interventions for community-based DRR mainstreaming in Bangladesh

Presently, there is a worldwide discussion concerning the role of NGOs in addressing community-based disaster risk reduction. Global indices rank Bangladesh as the world’s fifth most hazard-prone nation. Natural hazards are an ever-present concern for rural farmers and coastal communities of the country, with limited access to infrastructure. More than 2,500 registered non-governmental organizations (NGOs) deliver community-level programs in Bangladesh; however, the majority of these NGOs are non-Disaster Risk Reduction (non-DRR) in their core business. This paper aimed to assess the role of their interventions in mainstreaming community-based DRR in Bangladesh. Researchers conducted a field study in Satkhira district, the most natural hazard-prone coastal zone in Bangladesh, and interviewed 45 respondents including community beneficiaries, local government bodies, and NGO officials using purposive sampling techniques. Authors also collected relevant documents of the selected NGOs, and analyzed them along with the primary data. For analyzing data, researchers used thematic analysis method with the assistance of NVivo12 software. Study findings reveal that many development programs of NGOs contributed to DRR through strengthening the communities’ capacity, but some program outcomes increased long-term vulnerability of the beneficiary community. NGOs could contribute to the communities’ resilience by including DRR principles and practices within their regular relief and development programs. It is expected that the study findings would provide directions to non-DRR NGOs for integrating DRR within their regular development programs. This would help manage the future hazard risks including overwhelming damage to lives, properties, livelihoods, and structures and build capacity rather than increase vulnerability in communities.

Assessing impact of salinity and climate scenarios on dry season field crops in the coastal region of Bangladesh

CONTEXTSoil salinity is the main environmental limiting factor for current agricultural farming systems in the Bangladesh coastal zone. Targeting crop selection to ameliorate its impact in food production is a priority to ensure food security, diversifying crop outputs and reducing smallholders' vulnerabilities. In this context, crop growth modelling emerges as a useful tool for exploring different scenarios for crop selection. OBJECTIVEStudying spatial and -temporal heterogeneity in salinity and crop productivity under different climate scenarios. METHODSA dataset from the Polder 30 located in the Bangladesh southwest coastal zone, including different farming systems (rice-maize, rice-mungbean, rice-sunflower) comprising two years (2017–2019), was utilized, together with polder-level contiguous layers of factors (i.e., salinity, elevation, precipitation), to create clusters representing different yield-limiting conditions. Two salinity scenarios were defined and included in a long term in-silico assessment to explore dry-season field crop options (maize, sunflower, and mungbean). APSIM models for maize, sunflower and mungbean, were selected to perform all the crop simulations. RESULTS AND CONCLUSIONSBased on yield, sunflower was the most stable choice under salinity and maize was the best under non-saline conditions. Lastly, yield stability was accounted for different climate conditions, showing a large yield reduction for maize when combining low precipitation and high temperature, whereas mungbean and sunflower presented less sensitivity to different climates. SIGNIFICANCERight crop selection for the right environment, considering both salinity restrictions and climate uncertainties, is critical for long-term yield stability. The present study provides a novel framework to better match the most suitable crop under challenging salinity restrictions and climate uncertainties affecting smallholders in the coastal zone of Bangladesh.

Rural households' food security and its determinants in coastal regions of Bangladesh

AbstractThe coastal zone of Bangladesh is suffering from a wide range of climate change‐driven hazards. Limited attention has been given to these zones' food security assessment. Therefore, this study aims to assess the status of food security and its determinants among different groups of Bangladeshi coastal households. It also identifies their livelihood risks and coping strategies during stressed situations. Data were collected from 1350 households from coastal districts through a questionnaire survey. Food security was calculated and compared with the recommended average (2400 kcal/capita/day). A binary logit model was used to identify the determinants of food security among rural coastal households. Livelihood risks and coping mechanisms were recorded through open‐ended questions. The findings of this study revealed that although on average, sampled households were food secure (2753 kcal/capita/day), 81% of landless households and 72% of marginal landholders within the sample appeared food insecure. Among various food items, rice supplied the greatest total daily calorie intake (1841.47 kcal), second was the edible oil (172.27 kcal). The regression model revealed that farm size, farm income, off‐farm income, and crop production had positive impacts on households' food security. Floods, salinity, heavy rainfall, and reduction of land productivity were high risks to the large farm households, while heavy rainfall, floods, and salinity were high risks to the landless farm households. To cope with these risks, the majority of large farm households used their savings and sold livestock and poultry as coping strategies. The landless and marginal farmers were mostly helped by nongovernmental and government‐run organizations, moved elsewhere to find work, sold their labor, and were involved in fishing. It was concluded that different groups of farmers face different challenges. Our findings indicate that in order to protect landless and marginal farmers, government should implement policies aimed at increasing crop production by means of prioritizing saline‐tolerant crop varieties and the creation of more job opportunities.

Delineation of Bangladeshi coastal rice germplasm based on qualitative phenotypic traits

AbstractA detailed study of rice genetic resources in Bangladesh's coastal areas is necessary. This understanding is a necessary requirement for its utilization in selective breeding. The study reports on the qualitative morphological trait-based assessment of 150 local rice samples collected from Bangladesh's coastal zone, including 50 advanced lines developed from coastal germplasm. Six of the thirteen analysed characters had a substantial gene contribution, whereas the average was 0.694. The most impressive diversity was in leaf blade intensity of green colour (LBIGC: 0.705). The total morpho-qualitative diversity was calculated to be 0.412. The character efficiency content ranged from 0.655 (LBIGC) to 0.136 (Leaf Sheath: Anthocyanin colouration, Leaf Blade: Presence/Absence, and Leaf Blade: Anthocyanin. Colouration). As per the morphological variance study, 93% of morphological changes were detected within individuals, whereas 7% were found in populations. The 150 germplasm samples were divided into four subpopulations using STRUCTURE-based population analysis. A moderate genotypic difference was detected amongst all groups, with an Fst value of 0.111. The G statistic backed up the record as well. The Shannon mutual information index reached a value of 1.252 between populations 2 and 3. In terms of gene exchange, the highest value was found between populations 3 and 4. Our data indicate a high degree of diversity in Bangladesh's coastline rice germplasm. The findings will aid in conferring the farmers' Intellectual Property Rights on the investigated rice germplasm.

ADAPTIVE STRATEGIES OF COASTAL PEOPLE IN RESPONSE TO CLIMATE CHANGE: EXPERIENCES FROM TWO VILLAGES OF DACOPE UPAZILA IN BANGLADESH

Coastal zone of Bangladesh is vulnerable to different disasters due to global climate change. However, the vulnerability magnitude and impact of climate change has been hardly assessed focusing livelihood issues. Thus, this study was carried out to assess the impacts of the climate change and to find out the existing adaptation strategies at two villages of Dacope upazila in Khulna district of Bangladesh involving purposively selected 100 farmers. A survey was conducted using a pre-tested structured interview schedule. It was found that the highest proportion of the respondents (77%) belonged to low-income group (˂50,000 BDT i.e., 587.98 USD family-1). Villagers faced water stagnation, flood, high salinity, and severe drought during summer. These natural disasters damaged the crops, livestock, poultry, trees, houses, roads and shrimp water bodies. Probable solutions to mitigate the disasters would be construction of strong bunds, collecting and storing fresh water through digging small farm ponds, using the stored water for irrigation, training for awareness building, invention of alternate sustainable technology, excavation of canals and GO-NGO collaboration. Farmers reported that rainwater harvesting, hanging vegetable gardening, gher/embankment gardening, domestic animal rearing, handicrafts, etc. were some viable livelihood options. Development and release of new crop varieties, protection of the Sundarbans and awareness building through motivation might be some coping strategies for future extreme weather events.

Short-Term Waterlogging Depresses Early Growth of Sunflower (Helianthus annuus L.) on Saline Soils with a Shallow Water Table in the Coastal Zone of Bangladesh

Sunflower (Helianthus annuus L.), which is widely grown globally for its high-quality edible oil, is reasonably salt and drought tolerant but it is susceptible to waterlogging. In the saline coastal zone of the Ganges delta, sunflower is often exposed to sudden heavy rainfall during early growth but plant tolerance to such events is not known. Hence, we evaluated the effect of short-term soil inundation (referred to as waterlogging) for 0, 24, 48 and 72 h on sunflower at emergence, 2-leaf, and 4-leaf stages in early- and late-sown crops under field conditions (saline, clay-textured soil, and shallow groundwater). Waterlogging for 24 h did not affect sunflower at any stage but waterlogging for 48 and 72 h suppressed emergence and growth at the 2 and 4-leaf stages. Waterlogging for 72 h completely prevented the emergence for early sowing, whereas emergence was less affected for later sowing. Shoot and root dry weight were most affected at the emergence and 2-leaf stage, not at the 4-leaf stage. In conclusion, waterlogging caused by more than 24 h soil inundation at up to the 4-leaf stage severely depressed emergence and growth, indicating the need for effective drainage at sowing of sunflower in the low-lying coastal saline zone of Bangladesh.

Determinants of climate change adaptation strategies in the coastal zone of Bangladesh: implications for adaptation to climate change in developing countries

Considering the growing threats of climate change, in addition to mitigation strategies, it is highly and equally critical to understand the socio-economic determinants of climate adaptation in order to develop climate adaptation policies. This study makes a first attempt to explore the determinants of adaptation to climate change and choices of adaptation strategies at a larger spatial scale of the south-west coastal areas in Bangladesh, which is one of the most climate-vulnerable regions in the world. We employ both qualitative and quantitative approaches in order to examine farmers’ perception of climate risks, determinants and choices of adaptation strategies to climate change in six coastal districts of Bangladesh. Farmers are adapting to these situations using their knowledge and experience. The study reveals that a number of adaptation strategies have been taken to reduce the negative impacts of climate change. These adaptation strategies are categorized into four groups: crop management, water management, land management, and income diversification. Availability of inputs, high production cost, agricultural extension service, and proper adaptation knowledge and experiences were noted as the main non-climatic challenges, as well as different climatic factors in agricultural adaptation strategies. Statistical analysis indicates that the different socio-economic determinants of farmers significantly influence their choices of adaptation to climate change. Farmers adopt these adaptations mostly autonomously rather than on the advice of government. This study could be useful for developing national adaptation policies in Bangladesh and other similar developing countries.

Vulnerability and Capability of Disaster Risk Reduction in Hydro-meteorological Hazards-stricken Areas of the Coastal Zone in Bangladesh: the Case Study of the District of Patuakhali

Vulnerability and Capability of Disaster Risk Reduction in Hydro-meteorological Hazards-stricken Areas of the Coastal Zone in Bangladesh: the Case Study of the District of Patuakhali

Impact of Rice Straw Mulch on Soil Physical Properties, Sunflower Root Distribution and Yield in a Salt-Affected Clay-Textured Soil

Puddling of clay soils for rice transplanting causes a loss of soil structure and vertical shrinkage cracks that are hypothesized to hamper sunflower root growth in the following dry season. To alleviate soil constraints for sunflower root growth and yield, we examined the effects of three levels of mulch and two irrigation regimes in the dry season on a clay-textured soil in the coastal zone of Bangladesh. These treatments were no-mulch, rice straw mulch at 5 t ha−1 and 10 t ha−1, irrigation applied to the field capacity (I1) and a water supply double that of the I1 treatment (I2). The rice straw mulch significantly increased soil water content by 3–9% and decreased soil penetration resistance by 28–77% and crack volume by 84–91% at A 0–30 cm soil depth relative to the no-mulch treatment. The better root development with the rice straw mulch increased sunflower yield by 23%. No benefit or further reduction in soil penetration resistance or yield improvement was obtained from increasing the level of mulch from 5 to 10 t ha−1 or the volume of irrigation water. It is concluded that ameliorating soil constraints by mulch application led to better root growth in the upper root zone and the increased yield in the clay soil.