Exploring Water Table Dynamics for Sustainable Crop Production: A Case Study of Maize and Black Gram in the Kandi Region

Abstract

This study establishes the relationship between the water requirements of crops and reservoir management in one of the most fertile regions of the world—Kandi, India. Utilizing simulations built in a computing notebook, we analyze the water table dynamics for crops, specifically maize and black gram, alongside the depth of a canal feeding a reservoir over time. The findings highlight the temporal changes in water availability and the impact of drought on agricultural sustainability. Graphs generated through the analysis effectively illustrate these dynamics, providing insights into water management strategies that can enhance crop resilience and optimize resource utilization in environments prone to depleting water resources.

Introduction

Globally, there is evidence of the effects of climate change on agriculture; however, nations such as India are particularly vulnerable because of their large agricultural population, overuse of natural resources, and inadequate adaptation strategies. India’s warming trend over the last century has shown a 0.60°C increase. Food security may be impacted as a result of the anticipated effects, which are likely to exacerbate variations in many crops. In certain regions of India, the output of wheat and pulses has already been shown to be negatively impacted by rising temperatures, higher water stress, and fewer rainy days. Such dangers pose a serious risk to India’s agriculture-based economy, which is why irrigation and water conservation are essential.

Although maize is the main crop in many areas due to its resilience, it is susceptible to changes in water supply and temperature. Higher temperatures have been linked to poorer yields, especially during the crucial flowering and grain-filling stages. Similar difficulties affect black gram, an important pulse crop; these include rising drought conditions and rainfall variability, which can reduce productivity and jeopardise the food security of vulnerable populations.

The negative impacts of climate change go beyond lower yields. For example, higher temperatures and humidity aggravate the prevalence of pests and diseases that affect both black gram and maize. Furthermore, the long-term sustainability of these crops is seriously threatened by nutrient depletion and soil degradation brought on by unpredictable weather patterns. Considering how vital maize and black gram are to the local diet and how they sustain farmers’ livelihoods, creating resourceful irrigation and water management techniques is crucial to preserving agricultural resilience in the face of these difficulties.

Area of study

Kandi, situated in the Punjab and Jammu Kashmir regions of India, is one of the country’s most fertile areas, producing 573.19 lakh tonnes of maize and black gram in the 2022-2023 crop year. However, this region is facing a severe decline in water resources due to climate change and the over-extraction of groundwater.

Climate

The region’s climate ranges from semi-arid to sub-humid. The highest average temperature, reaching 41 °C, is recorded during the first two weeks of June, while the lowest average temperature, at 6 °C, occurs in January.The region receives average annual rainfall of 800-1500 mm with a very high coefficient of variation.

Soils

The soils in the region, primarily loamy sand to sandy loam, exhibit low to medium moisture retention and are highly erodible, with inherent fertility being very low and limited organic carbon content.

Crops and cropping systems

Maize is the dominant crop in the Kandi area, covering around 46,000 hectares, along with key kharif crops like pearl millet and black gram. The region also grows major rabi crops such as wheat and lentil, and supports diverse fruit production.

Problems in the agriculture

Erratic Rainfall: The region experiences annual rainfall of 800-1500 mm, with about 80% occurring during the kharif season (July-September). Rainfall is highly variable, often leading to droughts, especially during sowing. A significant chance (55-98%) of dry spells exceeding six days exists monthly, and pre-monsoon showers in June are unpredictable, delaying kharif sowing and impacting yields. Early monsoon withdrawal can also lead to severe droughts, complicating the establishment of subsequent rabi crops due to inadequate moisture.

Soil and Water Erosion: The area is characterized by hilly regions, seasonal streams (choes), and cultivated zones, with gullies and rills commonly present. The low organic carbon content (<0.04%) makes the soil highly dispersible and erodible, causing 30-40% of rainfall to result in runoff and water erosion.

Model Development and Methodology

The research aims to design an irrigation model for the study area, seen in Figure 1, that utilizes real-time data to optimize water application. By integrating soil moisture sensors and local terrain features with weather data, this approach seeks to revolutionize irrigation practices.

Employing a combination of remote sensing, data analysis, and modelling techniques, the project creates a model that assesses soil moisture, weather patterns, and crop water requirements to generate optimal irrigation schedules. The goal is to significantly reduce water consumption while enhancing crop yields.

Irrigation Model Software

The irrigation model was developed and executed using Python, utilizing libraries like NumPy for mathematical calculations and Matplotlib for visualizing water table dynamics. Additionally, ArcGIS was employed to map the terrain and analyse spatial data. This combination of tools allowed for accurate simulation of water dynamics and crop irrigation needs, helping to optimize water usage for maize and black gram crops.

Graphs and Results

Drought Period (Hour 50 to Hour 120): The water table graph for maize and black gram matches the highlighted yellow area seen in Figure 3, between hours 50 and 120, which plainly shows a protracted period without rainfall. Water stress for both crops is exacerbated at this time due to the decline in water table levels caused by the absence of rainfall.

Post-Drought Rainfall Spike: There is a discernible increase in rainfall after the drought, indicating an abrupt entry of water to the area. The low water table readings in the following graphs, however, suggest that this rainfall may not be enough to restore the ideal water levels for agricultural development given the earlier depletion of the water table.

Correlation with Crop Water Usage: The period of higher water consumption seen in both black gram and maize coincides with the absence of rainfall during the hours highlighted. This emphasises the necessity of efficient water management plans to lessen the effects of these dry spells and guarantee that crops continue to be resilient even in the face of infrequent rainfall.

Initial Water Availability: Over the course of the first two days, maize’s water table levels constantly exceeded those of black gram, suggesting that during its early growth phase, maize needs more water.

Drought Impact Period (Days 2-5): The yellow shaded area represents the dramatic decline in water table levels that both crops experienced between

Days 2 and 5. This indicates a time of heightened drought or water stress that is affecting the availability of water for both crops. Interestingly, maize maintained a little higher water table than black gram even throughout this dry period, highlighting its higher water requirement.

Post-Drought Water Levels: After day 5, there was a noticeable decline in the amount of water available, with the water table of maize falling below that of black gram. This suggests that the crop might have been more affected by the prolonged drought or that the water resources may have been rapidly depleted due to maize’s water requirements.

Implications for Irrigation Management: The general downward trend in both crops’ water table levels highlights the necessity of implementing focused irrigation techniques to promote crop growth, particularly in times of drought. By comprehending these dynamics, water allocation may be optimised to guarantee that both crops receive enough moisture for growth.

Initial Inflow Phase: The increase in reservoir level in the first two days of the simulation is indicative of an efficient canal inflow of water, which is essential for supplying maize and black gram with the irrigation they require in their early growth stages (see Figure 4).

Stability Period: Consistent soil moisture levels are ensured between days two and five due to the relative stability in depth, which is essential for improving crop health and yield potential.

Peak Depth Observations: The peak depth attained by day 7 indicates a sufficient supply of water, offering chances for well-timed irrigation scheduling that coincides with crucial stages of crop growth.

Recommendations for Adaptive Management: Constant monitoring of reservoir levels is necessary to make real-time adjustments to irrigation techniques, which maximises water allocation and reduces crop stress, particularly in advance of dry spells.

Agricultural Sustainability Consequences: Reservoir dynamics insights emphasize the significance of efficient management of water resources, which can boost crop resilience, maximize resource use, and increase food security in the face of climate instability.

A reservoir of water supports irrigation as designed during the simulation (see Figure 5). The irrigation network has a visible effect on average water table level as seen in Figure 6.

Proposed Solutions for Enhanced Water Management

Effect of Drought on Water Table Levels

During the simulated dry spell (days 2 to 5), the data shows a significant drop in the water tables for black gram and maize. Maize exhibits a slower recovery of the water table post-drought compared to black gram, which can be attributed to its greater water needs, while black gram displays greater adaptability. This decrease demonstrates the substantial effect that protracted dry weather has on crop water availability, ultimately impacting crop growth and productivity.

Solution: It is critical to use efficient irrigation scheduling and water-saving measures, such as drip irrigation, to preserve soil moisture during these dry spells. Introducing crop types resistant to drought may also improve resistance to water stress.

Reservoir and Canal Management

The water level graphs show variations, with a noticeable period of stability throughout the drought (seen by the yellow-shaded area). This implies that reservoirs are essential for acting as water scarcity buffers.

Solution: To guarantee sufficient water storage for use during the dry seasons during the rainy season, better reservoir management techniques are necessary. Stable water levels may be maintained and sharp fluctuations in availability can be avoided with regular monitoring of canal inflow rates.

Rainfall Dependency and Variability

The rainfall data highlights the region’s dependence on erratic rainfall patterns that have a direct impact on crop water supplies. It also reveals a sharp rise in rainfall after a protracted dry spell (between hours 50 and 120).

Solution: By installing rainwater harvesting devices and enhancing soil water retention techniques, farmers may lessen their reliance on erratic rainfall and give their crops a more reliable supply of water during dry seasons.

Efficient Water Resource Utilization

A comparative study shows that maize tends to use up water resources more quickly than black gram, pointing to the latter’s higher water requirement and possible sustainability problems during dry spells.

Solution: Crop rotation techniques that combine water-intensive crops like maize with drought-tolerant crops like black gram, can maximise water consumption while preserving soil moisture.

Overall, these preliminary findings suggest that the proposed model could decrease water usage, offering a practical solution for areas like Kandi facing water scarcity. By simulating various rainfall scenarios and their effects on water availability, this model provides critical insights for conserving water and promoting sustainable agricultural practices.

Conclusion

The relationship between crop water demand, reservoir management, and water availability in India’s Kandi region is clarified by the research model. It illustrates how drought times have a major impact on crop water intake, especially for black gram and maize, with maize needing noticeably more water, by simulating water table dynamics. Although efficient reservoir management has been key to mitigating the effects of drought, stable crop yields remain elusive due to the unpredictability of rainfall patterns. Because of the model’s adaptability, it can be used to simulate different crops and produce customised insights about their water requirements and drought resilience.This is achieved by incorporating crop-specific coefficients and parameters, such as root water uptake rates, soil porosity, evapotranspiration rates, and crop growth stages, which allow the model to generate tailored insights for various crops.

The results emphasize the critical need for sustainable water management solutions, such as enhanced irrigation practices, rainwater collection, and the development of drought-tolerant crops, in order to increase agricultural resilience in this semi-arid area. The research shows a feasible way to improve water usage efficiency and guarantee continued agricultural productivity in areas vulnerable to water constraint by utilising these adaptive tactics.

References

• Alagh, Y. K. (2013). The Future of Indian Agriculture. National Book Trust, India.
• Government of Punjab, Irrigation Department. (2015). Kandi Master Plan: A Comprehensive Flood Management Plan for the Kandi Area. Retrieved from https://irrigation.punjab.gov.in/kandi-master-plan
• Indian Council of Agricultural Research (ICAR). (2021). Efficient Water Management in Agriculture – Challenges and Opportunities. Retrieved from https://icar.org.in
• Indian Meteorological Department (IMD). (2020). Rainfall and Temperature Data of Punjab (2010-2020). Retrieved from https://www.imdpune.gov.in
• Singh, N. P., & Verma, A. (2019). Socioeconomic impacts of climate change on agriculture in India. International Journal of Agricultural Economics, 5(2), 99-112.
• Kumar, R., Sidhu, P. S., & Sharma, B. D. (2005). Mineralogy of soils of the Kandi area in the Siwalik hills of semi-arid tract of India. Agropedology, 15(2), 40-50.
• Pathak, H., Nayak, A. K., Jena, M., Singh, O. N., Samal, P., & Sharma, S. G. (2020). Socioeconomic Impacts of Climate Change on Agriculture in India. Agricultural Research Journal, ICAR.
• Rathore, A. L., & Dabas, J. P. S. (2018). Rainwater Harvesting: A Sustainable Water Resource Management Strategy. Water Research Institute.

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