Bund Height Research Articles

Pest Rodents’ Responses to Rice Farming in Northern Peninsular Malaysia

Pest rodents significantly reduce crop yields globally each year, necessitating an efficient rodent management program. In small rice-producing nations like Malaysia, these rodents might lead to food insecurity, thus a science-based pest rodent management strategy is crucial. We attempted to identify the key habitat structure that affects rodent pest populations by investigating the relationships of rodent pest populations with farming practices, site-level habitat, and landscape characteristics. We found that rodent abundance in the rice fields was positively correlated with bund height and width. In addition, rice growing stages and planting seasons affected rodent abundance. However, rodent abundance was negatively related to the distance from active burrows to residential areas. As an alternative to chemical control, we suggest that trapping exercises with a covered trap should be conducted around active burrows located nearby residential areas, with high and wide bunds during early rice planting stages in the dry rice planting season.

Performance Assessment of Tractor-operated Bund Former for Mulched Field

Managing paddy field loaded with straw before wheat sowing in paddy-wheat crop production system is cumbersome due to various operations involved in the process. Bund forming for irrigation remains difficult among these operations due to mulched conditions. Simultaneous removal of straw (up to 1.25 m width), soil pulverization, and trapezoidal-shaped soil bund forming in one pass is required. Field evaluation of a tractor-operated bund former for mulched fields was conducted to observe the effects of rotor speed ratios (3:1, 4:1, 5:1), opening width of bund forming plates (270, 340, 410 mm), and straw loads (4.0-4.5, 6.0-6.5 t.ha-1) on the pulverization index (mm), height of bund (mm), width of bund (mm), fuel consumption (l.h-1) and field capacity (ha.h-1) of the machine. The effects of rotor speed ratio, opening width of bund forming plates, and straw load were significant (p<0.05) on pulverization index, bund height, bund width, and fuel consumption. Best performances were obtained at rotor speed ratio of 4:1 and bund forming plates opening width of 340 mm under both straw loads. This combination gave the optimum height of bund (277.6 mm), bund width (720 mm), pulverization index (12.76 mm), and fuel consumption (7.05 l.h-1) under both straw loads. The effective field capacity of the tractor-operated bund former was 1.17 ha.h-1 at forward travel speed of 1.5 km.h-1. The operational cost of the bund former was 792.36 ₹.ha-1.

Runoff and soil loss responses of cultivated land managed with graded soil bunds of different ages in the Upper Blue Nile basin, Ethiopia

BackgroundIn view of a wide range of on-site and off-site impacts of soil erosion, different soil and water conservation measures have been implemented mainly over the last two decades in the Gumara watershed and Ethiopia at large. But their effects have not been sufficiently documented, and maintenance of structures received very little attention. This study investigated the effectiveness of graded soil bunds of zero and 11 years of age in reducing runoff and soil loss. Six hydrologically isolated experimental runoff plots (three treatments × two replicates) were prepared to observe rainfall, runoff, and sediment concentrations in the 2019 summer rainfall season (covering approximately 70% of the annual rainfall).ResultsNewly constructed soil bunds reduced runoff by 34.94 and 25.56% compared to the old and non-treated counterparts, respectively. Similarly, 59.6 and 48.3% soil loss reductions were observed. The amount of soil loss in non-treated plots was twice that from the new plots and even 1.6 times higher than that from the old-graded soil bund treatments. The rate of soil loss in the new- and old-graded soil bund-treated and non-treated plots was 23.5, 45.6, and 58.1 t ha−1 year−1, respectively. However, the effectiveness of the old soil bunds was much lower (only − 12.6 and − 21.7% in runoff and soil loss, respectively) than its new equivalent. Graded soil bunds, in its new form, reduced runoff, runoff coefficient, and soil loss significantly (P < 0.05). Regardless of the treatments, from the start of the rainy season to the end, runoff and runoff coefficient showed an increase, but sediment concentration decreased. Newly constructed soil bund is the most effective in reducing runoff and soil loss.ConclusionGraded soil bunds reduced runoff and soil loss significantly, but the rate even in the treated plots was very high when compared to both the soil loss tolerance (1–6 t ha−1 year−1) and formation rate (10–14 t ha−1 year−1) estimated for the area. Hence, these structures need to be supported by other measures such as grass strips, agro-forestry, and percolation ditches, for better results. Besides, regular maintenance by either removing sediments from bund furrows or increasing the bund height is recommended for sustained reduction of runoff and soil loss.

Participatory Demonstration and Evaluation of Integrated Maize-Forage Production and Soil Conservation through Forage Legumes under Sowing and Grass Strips on Soil Bunds

Soil conservation through integrating legumes with grain crops, and grass strips on soil bunds is an important option for food and feed security of human and livestock respectively. Based on this notion, this research activity was conducted with objectives of improve productivity of land and livestock through the integrated conservation and farm management, demonstrate integrated maize-forage production, and practices of soil and water conservation practices and improve soil fertility through the biological and physical conservation practices from 2016 to 2018 main cropping season in selected sites Kile, Adada1 and Wahil kebeles. The trial was conducted following the procedure of Randomized Control Block Design on three farmers’ fields at each site where farmers are used as replication. Soil bunds extending 20m across contour were constructed on each farm of three farmers. The design of structure was based on the slope of the land which encompasses bund height 70cm and bund width 50cm to protect over toping of flood and increases water retention in the soil. This research found that maize yield 2447.2 kg/ha, 3311.13kg/ha and 3808.66kg/ha; fresh weight of elephant grass 15, 400kg/ha, 6150kg/ha and 20,200kg/ha; and pigeon pea 8200kg/ha, 9620kg/ha, 13800kg/ha an increasing trend across sites throughout three years from the constructed soil bund with integrated system. Soil laboratory analysis also shows an increasing organic matter, available phosphorus and nitrogen because of these integrated systems. Therefore, promoting this integrated system is recommended to small holder farmers by government, Nongovernment and other stakeholders. Key words: Soil bund , Elephant grass, Pigeon pea, Conservation DOI: 10.7176/FSQM/100-02 Publication date: August 31 st 2020

Determination of Maximum Storage and Drainage Coefficient from Consecutive Days Maximum Rainfall at Different Locations in India

Knowledge about the maximum possible storage of rainwater in the field and its safe disposal is very important to save crops from the adverse impact of excess rainfall. Keeping this in view, daily rainfall data of 30 to 35 years as per availability was analyzed at four centres of All India Coordinated Research Project on Water Management i.e. (i) Samastipur (ii) Ludhiana, (iii) Hisar, and (iv) Almora. In the design of agricultural structures, generally, 10 years return period is considered, so the point, where tangent drawn on the curves of 10 years return period crosses the Y-axis, gives maximum possible storage (recommended bund height) in rice fields. Maximum possible storage (bund height) corresponding to 10 years return period was found as 25 cm, 15 cm, 13 cm, and 27.5 cm and corresponding drainage coefficient as 26.3 mm/day, 6.8 mm/day, 8.4 mm/day and 24.8 mm/day for Samastipur, Ludhiana, Hisar and Almora, respectively.

Determination of Drainage Coefficient and Bund Height of Rice Fields at Gaya and Bhagalpur Districts in Bihar

Rainfall plays an important role in agricultural production, particularly in rainfed areas. Less occurrence of rainfall causes drought like situation and crops suffer due to deficit of water, whereas heavy rainfall occurring for longer duration lead to flood like situation resulting in more runoff, soil erosion and crop damage. Rice can sustain water for little longer period compared to other crops, but this crop also needs drainage. 30 years daily rainfall data was collected at Gaya and Bhagalpur districts and analyzed. Two parameter Gamma distribution model was found fitting well in 1 to 7 consecutive days maximum rainfall corresponding to return periods varying from 2 to 20 years. In order to determine drainage coefficient at Gaya and Bhagalpur districts, depthduration- return period curves were developed. Tangents were drawn on the curves from 100 mm, 150 mm and 200 mm points and slope of these tangents gave the drainage coefficients corresponding to these rain water storage levels. Since 10 years return period is generally considered in design of agricultural structures, so the poin ton Y axis, where tangent drawn on the curves of 10 years return period crosses, gives the bund height. For both Gaya and Bhagalpur bund heights were found as 24 cm and corresponding drainage coefficients as 12.5 and 25 mm/day.

Numerical investigation of bund overtopping under storage tank failure events

In this paper computational fluid dynamics simulations (CFD) were carried out in order to investigate the efficiency of bund designs and top wall deflectors (breakwaters) under several tank failure modes. Investigation was performed over laboratory scale configurations, some of them were also experimentally studied. Simulations were performed using the Volume of Fluid (VOF) method and literature data were used for assessing the solver prior to investigate the different bund designs. Numerical and experimental results agreed, showing the suitability of numerical methods to predict overtopping. The amount of liquid lost showed a low dependency with the containment shape (square, circular or rectangular), but a high one with the bund height. On the contrary, the use of breakwaters showed to be a suitable and very efficient way to reduce liquid loss, although inducing significant extra mechanical efforts over the bund walls.

Development of heavy vapour clouds in very low wind speeds

The majority of very large vapour cloud explosions occur in such low wind speeds that vapour flow is gravity-driven. The rate of stripping (or detrainment) of heavy gas by the wind is so low that almost all of the gas released remains in a gas “blanket”, which typically slumps in all directions around the source. Such gravity-driven flammable clouds may extend many hundreds of metres from the source in all directions without significant dilution: their development cannot be assessed with conventional windy dispersion models.Previous work on the basic problem of gravity-driven vapour transport on a flat open surface is reviewed. Existing methods suffer from a number of deficiencies including arbitrary specification of current height and velocity and the neglect of surface friction.A new method of analysis is presented. Close to the source the flow can be calculated from the initial conditions at the source by integration of momentum and continuity equations. Entrainment of fresh air and friction increase the stability of the flow (Richardson number) and the rate of dilution declines towards zero. When the Richardson number approaches unity the current becomes critical and further out from the source the flow is under downstream control.The new method is used to calculate the total dilution of a vapour cloud before entrainment of fresh air is completely suppressed. This determines whether clouds are flammable at long-range. The effects of surface roughness, bund height, vapour density etc. are described.Predictions are compared with data from incidents.

Effect of in-situ Moisture Conservation Methods on Productivity in North Eastern Ghat Zone of Odisha

The study was conducted in the Budhadani village of Kandhamal District in north eastern ghat zone of Odisha under the National Innovations on Climate Resilient Agriculture (NICRA) programme of AICRP for Dry Land Agriculture, Phulbani, Odisha during kharif 2014 and 2015. Budhadani village always experiences scarce and erratic monsoon rainfall during kharif season. Practice of sole cropping was predominant in this area and often resulted in low yields or sometimes crop failure due to erratic monsoon rainfall. In such areas, in-situ moisture conservation methods and intercropping system are feasible options to minimize risk in crop production and ensure reasonable returns. The study was conducted for the cropping system as such sole maize, maize + cowpea (2:2) intercropping and maize + pigeon pea (2:2) intercropping system. In this experiment, three in-situ moisture conservation methods such as (i) summer ploughing, (ii) increase bund height and (iii) both summer ploughing and increase bund height were compared with the control treatment with no moisture conservation measures. Among the different moisture conservation methods, summer ploughing with increased bund height resulted in higher yield as compared to control treatment and other moisture conservation methods. Intercropping of rainfed crops such as maize + cowpea and maize + pigeon pea is an important risk minimizing strategy for drought proofing in the scarce rainfall zones.

Estimating Irrigation Requirement for Rice Cropping under Flooding Condition using BUDGET Model

This study explored the effect of rainfall pattern and soil characteristics on water management in rice paddy fields, using a soil water balance model, BUDGET. In two sites with different soil textural group, coarse loamy soil (Gangseo series) and fine soil (Hwadong series), respectively, we have monitored daily decrease of water depth, percolation rate, and groundwater table. The observed evapotranspiration (ET) was obtained from differences between water depth decrease and percolation rate. The root mean square difference values between observed and BUDGET-estimated ET ranged between 10% and 20% of the average observed ET. This is comparable to the measurement uncertainty, suggesting that the BUDGET model can provide reliable ET estimation for rice fields. In BUDGET model of this study, irrigation requirement was determined as minimum water need for maintaining water-saturated soil surface, assuming 100 mm of bund height and no lateral loss of water. The model results showed different water balance and irrigation requirement with the different soil profile and indicated that minimum percolation rate by plow pan could determine the irrigation requirement of rice paddy field. For the condition of different rainfall distribution, the results presented different irrigation period and amounts, representing the importance of securing water for irrigation against different rainfall pattern.

Growth of multipurpose tree species (MPTS) as influenced by various soil moisture conservation techniques under rainfed conditions

The present experiment was conducted on medium deep silty loam soil to study the effect of rain water conservation techniques on growth of multipurpose tree species (MPTS) in terms of height and collar diameter. The experiment was conducted during the year 2012-2014 on AEEC Farm, Dr. Panjabrao Deshmukh Agriculture University, Akola with five treatments viz. , half-moon terracing (T 1 ), mulching with locally available grasses @ 10 kg/ plant (T 2 ), compartment bunding with bund height of 0.15 m (T 3 ), use of soybean as cover crop (T 4 ) and control (T 5 ) and four replications in Randomized Block Design. The results revealed that plant height and collar diameter of tree species were found significantly highest in half moon terracing (T 1 ) followed by mulching with locally available grasses @ 10 kg/ plant (T 2 ) as compared to other treatments. Soil moisture content of Karanj, Sitaphal and Bel at different soil depths was also found highest in half-moon terracing (T 1 ) and mulching with locally available grasses @ 10 kg/ plant (T 2 ).

A water balance model for rainfed lowland rice fields emphasising lateral water movement within a toposequence

In the Mekong region, most rice paddies lie in gently sloping lowlands. An accurate estimate of paddy water availability is crucial for modelling rice ( Oryza sativa L.) productivity in such environments. However, modelling of water balance in the sloping lowlands can be difficult due to problems in estimating lateral water movement from high to low positions in the toposequence. This paper describes a semi-empirical model for estimating net lateral water flow along a toposequence of rice fields. Net lateral water flow is separated into three sub-components: (i) lateral seepage through the bunds from field to field; (ii) surface runoff over the bunds from field to field; (iii) water run-on from the catchment above the toposequence. The lateral seepage is estimated using the Dupuit equation for steady unconfined flow. Surface runoff over the bund is calculated as excess water depth above the bund height, while run-on from the catchment is calculated using a rainfall–runoff relationship. The other water balance components used in the model are rainfall (measured), paddy evapotranspiration (ET), and downward water flow (within the field and under the bund). Paddy ET is estimated using the FAO crop ET model. The downward water flow is empirically determined for soil texture groups. Simulation results showed that field water levels computed by the model varied between the bund height (maximum) and the hardpan level (minimum). The daily change in the water level was satisfactorily validated using data collected from a field experiment in a toposequence in Cambodia. The component governing the water balance in the higher toposequence positions was the downward water flow (45% of seasonal rainfall at the top of the toposequence). However, the water balance in the lower positions was affected largely by the net lateral water flow (21% of seasonal rainfall at the bottom of the toposequence). Seasonal ET was 67–69% of seasonal rainfall.

Monitoring Surface Soil Moisture in Post‐Harvest Rice Areas Using C‐band Radar Imagery in Northeast Thailand

The objective of this study is to estimate the residual surface soil moisture of rice fields after harvesting, in Northeast Thailand, using C‐band SAR images. Such information is useful to determine possibilities of cultivating additional short‐cycle crops after the harvesting of the main rice crop. To accomplish this objective this study exploits three C‐band SAR images acquired over the test area along with simultaneous ground measurements collected in support of analysis of the SAR images. The main parameters measured on the ground were: the volumetric moisture content of the soil using time domain reflectrometry (TDR), the surface roughness, using profile data, and residue cover. Other field environmental factors that might affect radar backscattering, including the topography of rice terraces (elevation, slope, and aspect), bund height between rice fields, soil types, and density of sparse tree stands were also acquired and registered to the image data. Before the analysis, the SAR images were calibrated, registered, and then filtered using multitemporal and spatial filters to reduce variability of the radar backscattering coefficient due to speckle. The measured soil moisture values were then correlated with the radar backscattering coefficients of the experimental plots and the results interpreted in terms of the main environmental factors. Varying residue cover and field aspect angles were found to significantly affect the relationship between radar backscatter and soil moisture content and therefore had to be taken into account before inverting the image data into soil moisture maps. Overall it was found that two soil moisture classes could reliably be separated using the SAR images, and that soil moisture maps could be obtained through a simple inversion technique based on applying a threshold to the SAR images. Analyses of these resulting moisture maps indicate that SAR data is useful to monitor and map surface soil moisture in rice fields after harvest.

Development of a Water Budgeting Procedure to Estimate Drainage Coefficient for Coastal Paddy Areas

A water budgeting procedure was developed taking field gradient and bund height into consideration for the determination of drainage coefficient for coastal paddy areas. Various water budge components were computed based on simple methods requiring limited meteorological parameters that are commonly available in India. This approach was compared with modified USDA SCS-CN method, which assumes a constant curve number for estimating runoff from paddy fields. Water budgeting procedure proved to be superior as compared to the USDA SCS-CN method for generation of daily runoff depth (drainage coefficient) for paddy growing coastal areas.

Combining crop modelling with economic risk-analysis for the evaluation of crop management strategies

An agro-ecological approach is presented for the evaluation of alternative management options for rice production in the light of farmers attitudes towards risk. The approach combined eco-physiological crop growth modelling with stochastic dominance theory and is illustrated for a case study of rainfed lowland rice in Victoria, Tarlac Province, the Philippines. The eco-physiological rice growth model ORYZA_W was used to estimate probability distributions of rice yields under different management scenarios. Relatively simple management options were considered for soils with different water storage capacities: plant density; seedling age at transplanting; bund height; and puddled soil depth. Stochastic dominance analysis was applied to identify risk-efficient management options. A critical appraisal of the proposed agro-ecological method for risk-analysis is given and suggestions are made for refinement and further research.