SECTION A
Q - Give two institute involved in soil and water conservation ?
A - AICRPDA: All India Coordinated Research Project for Dryland Agriculture.
CAZRI: Central Arid Zone Research Institute, Jodhpur
CSWCR&TI: Central Soil and Water Conservation Research and Training Institute at Dehradun.
ICRISAT: International Crops Research Institute for the Semi-Arid Tropics, Hyderabad
CGIAR: Consultative Group on International Agricultural Research
CRIDA: The Central Research Institute for Dryland Agriculture, Hyderabad
NWDB: National Wasteland Development Board
NRAA: National Rainfed Area Authority
IWMP: Integrated Watershed Management Programme
Q - Define Drought. what is difference between Aridity and Drought ?
A - Drought is a prolonged period of deficient rainfall relative to the statistical multi-year average for a region. This deficit can result in significant impacts on agriculture, water supply, ecosystems, and overall socio-economic conditions.
Q - Write short note on broad bed furrows (BBF) ?
A - The Broad Bed and Furrow (BBF) system is an agricultural practice designed to improve water management, soil conservation, and crop yields in rainfed and semi-arid regions. It involves creating broad, raised beds with furrows in between. Here are the key features, benefits, and implementation details of the BBF system:
### Key Features of the BBF System:
1. **Raised Beds**: Broad, elevated strips of soil (usually 1 to 1.5 meters wide) where crops are planted.
2. **Furrows**: Narrow channels (usually 0.3 to 0.5 meters wide) between the beds that facilitate drainage and water conservation.
### Benefits of the BBF System:
1. **Improved Drainage**: The furrows help to drain excess water during heavy rains, reducing waterlogging and root diseases in crops.
2. **Enhanced Soil Moisture**: In times of low rainfall, the furrows can act as mini-reservoirs, allowing water to infiltrate slowly into the soil, thereby maintaining soil moisture for crops.
3. **Erosion Control**: The structure of the beds and furrows reduces soil erosion by minimizing runoff and allowing more water to percolate into the soil.
4. **Increased Crop Yield**: By managing water more effectively, the BBF system can lead to better crop growth and higher yields, especially in rainfed agriculture.
5. **Soil Health**: The system can improve soil structure and health over time by preventing erosion and promoting organic matter accumulation.
Q - Give the classification of Gullies ?
A - Gullies are channels or ravines formed by the concentrated flow of water, often as a result of surface runoff, which erodes soil and underlying material. The classification of gullies can be based on various criteria such as their stage of development, shape, size, and the processes driving their formation.
Classification Based on Development Stage:
Initiation Stage:
Rills: Small, shallow channels that can develop into gullies if erosion continues. They are typically less than 30 cm deep and can be easily obliterated by normal farming operations.
Incipient Gullies: Slightly larger than rills, these channels begin to form distinct banks and are not easily removed by standard tillage.
Active Stage:
Active Gullies: These are well-defined channels that are actively eroding and expanding. They have steep sides and a noticeable headcut, and their formation is typically driven by continuous water flow and soil erosion.
Q - Describe the effect of drought on crop production .
A - The effect of drought are -
Water relations: Water deficit alters water status and affects absorption,
translocation, and transpiration.
Photosynthesis: Photosynthesis is reduced due to lower photosynthetic rate,
chlorophyll content, and leaf area.
Respiration: Respiration increases initially but decreases with severe
drought.
Anatomical changes: Anatomical changes include smaller cell and
intercellular space size, thicker cell walls, and increased stomata per unit leaf.
Metabolic reaction: Almost all metabolic reactions are affected by water
deficits.
Hormonal Relationships: Growth-promoting hormones decrease while
growth-regulating hormones increase.
Nutrition: Nutrient fixation, uptake, and assimilation, especially nitrogen, are
affected.
Growth and Development: Decreased growth of leaves, stems, and fruits,
delayed maturity, and reduced reproduction and grain growth.
Yield: Yield is heavily influenced by drought timing and the proportion of
useful material harvested.Yield decreases.
Q - Give the importance of water harvesting.
A - IMPORTANCE OF WATER
HARVESTING
Water Security:
• Provides an additional water source in water-scarce regions.
• Mitigates drought impacts by storing rainwater for use during dry
periods.
Agricultural Benefits:
• Supports crop irrigation during low rainfall.
• Enhances crop productivity and reduces reliance on erratic rainfall.
Improved Water Availability:
• Increases water availability in areas with overexploited groundwater.
• Promotes sustainable water management and groundwater recharge.
Ecosystem Conservation:
• Restores ecological balance by replenishing natural water bodies.
• Preserve biodiversity, wildlife habitats, and ecosystem sustainability.
Groundwater Recharge:
Facilitates groundwater aquifer replenishment, a vital freshwater source.
Flood Mitigation:
Reduces flood risks by capturing and managing excess rainfall.
Domestic Water Supply:
Offers an alternative water source for drinking, cooking, and domestic use.
Climate Change Resilience:
It helps in managing water in the face of changing climate patterns.
Community Empowerment:
Involves communities in water harvesting projects, fostering cooperation
and ownership.
Section c
Q - Define Agronomic measure for soil and water conservation.
A - Agronomic measures for soil and water conservation are practices that enhance the sustainability of agricultural systems by reducing soil erosion, improving water infiltration, and maintaining soil fertility. These measures are often integrated into farming operations and can be highly effective in promoting soil health and water conservation. Here are some key agronomic measures:
### 1. **Contour Farming**
- **Description**: Planting along the contour lines of a slope rather than up and down the slope.
- **Benefits**: Reduces water runoff and soil erosion by allowing water to infiltrate the soil rather than flowing rapidly down the slope.
### 2. **Strip Cropping**
- **Description**: Alternating strips of different crops or a combination of crops and cover plants.
- **Benefits**: Reduces erosion by breaking up the flow of water and provides a barrier that captures soil particles. Different crops can improve soil structure and fertility.
### 3. **Cover Cropping**
- **Description**: Growing cover crops, such as legumes, grasses, or other green manures, during off-season periods.
- **Benefits**: Protects soil from erosion, improves soil structure, enhances soil organic matter, and helps in nitrogen fixation.
### 4. **Crop Rotation**
- **Description**: Growing different crops in succession on the same land to maintain soil fertility and health.
- **Benefits**: Reduces soil erosion, disrupts pest and disease cycles, improves soil structure and fertility, and enhances biodiversity.
### 5. **Mulching**
- **Description**: Applying organic or inorganic materials (like straw, leaves, or plastic) on the soil surface.
- **Benefits**: Reduces evaporation, improves water retention, minimizes soil temperature fluctuations, and protects soil from erosion.
### 6. **Agroforestry**
- **Description**: Integrating trees and shrubs into agricultural landscapes.
- **Benefits**: Reduces erosion, improves soil fertility through leaf litter and nitrogen fixation, provides windbreaks, and enhances biodiversity.
### 7. **Conservation Tillage**
- **Description**: Reducing the frequency and intensity of tillage to maintain soil structure and organic matter.
- **Benefits**: Decreases erosion, improves water infiltration, conserves soil moisture, and enhances soil organic matter.
### 8. **Terracing**
- **Description**: Creating stepped levels on steep slopes to reduce runoff and soil erosion.
- **Benefits**: Reduces soil erosion, increases water infiltration, and makes sloped land more suitable for agriculture.
### 9. **Grassed Waterways**
- **Description**: Establishing grass in natural drainage ways to slow down water flow and prevent gully formation.
- **Benefits**: Reduces soil erosion, improves water infiltration, and filters out sediments and pollutants from runoff.
### 10. **Alley Cropping**
- **Description**: Planting crops in rows with strips of perennial plants (usually trees or shrubs) in between.
- **Benefits**: Reduces wind and water erosion, enhances biodiversity, improves soil structure, and provides additional income from tree crops.
### 11. **Contour Bunding**
- **Description**: Constructing small earthen embankments along the contour lines.
- **Benefits**: Reduces runoff, enhances water infiltration, and minimizes soil erosion.
### 12. **Vegetative Barriers**
- **Description**: Planting dense strips of grasses or shrubs along the contour lines or field edges.
- **Benefits**: Reduces soil erosion, traps sediments, and enhances water infiltration.
### 13. **Rainwater Harvesting**
- **Description**: Collecting and storing rainwater for agricultural use.
- **Benefits**: Provides a supplementary water source during dry periods, improves water availability, and reduces runoff.
### 14. **Rotational Grazing**
- **Description**: Moving livestock between pastures to prevent overgrazing and allow vegetation to recover.
- **Benefits**: Reduces soil compaction and erosion, improves pasture productivity, and maintains soil health.
Q - Describe the crop adaptation and mitigation to drought ?
A - Crop adaptation involves various mechanisms:
1. ESCAPING DROUGHT - Some plants have a short life cycle and complete
their growth and reproduction within a limited period
of rainfall.
These plants germinate at the beginning of the rainy
season and complete their life cycle before the soil
dries up.
They do not possess specific mechanisms to
overcome moisture stress but rely on timing their
growth and development with available water.
2. DROUGHT RESISTANCE - Crop varieties or species that can grow and yield
satisfactorily in areas with periodic water deficits are
considered drought-resistant. These plants have
mechanisms to tolerate or withstand water stress.
3. STRESS AVOIDANCE - Stress avoidance involves maintaining a favorable water balance and turgidity even under
drought conditions, thereby avoiding the detrimental effects of stress. This can be achieved
by conserving water or accelerating water uptake
(A) CONSERVING WATER - Plants can conserve water by closing stomata, which reduces transpiration and water loss.
They may also have specialized adaptations such as storing water in tissues, developing
smaller leaves with a thick cuticle, increasing photosynthetic efficiency, having sunken
stomata with hairs (pubescence) to reflect light and reduce transpiration, shedding leaves
during periods of water scarcity, and reducing enzyme activity. Some plants may also
develop awns or thorns as protective adaptations.
(B) WATER UPTAKE - Plants adapt to drought by enhancing their water uptake capacity.
• This can involve the development of adventitious roots, which absorb water from deeper
soil layers,
• Increasing the length and density of roots.
• By improving hydraulic conductance, either by increasing the diameter or number of
xylem vessels, plants can enhance their ability to transport water from roots to shoots.
Q - Give the classification of drought based on relevance to the users ( National commission on Agriculture 1976 ).
A - Meteorological drought:
This occurs when there is less precipitation than normal over an area
for a prolonged period. This affects water availability for different
sectors, including agriculture.
• Atmospheric drought:
This occurs due to low air humidity and hot, dry winds. It can cause
wilting in plants during the hot part of the day when transpiration
exceeds absorption.
* Hydrological drought:
This occurs when meteorological drought is prolonged and results in
depletion of surface water and drying of reservoirs, tanks, etc. This
affects all sectors using water.
• Agricultural drought (soil drought):
This is caused by soil moisture stress due to an imbalance between
available soil moisture and evapotranspiration of a crop, affecting crops
during their growth stages.
