UP Board Solutions Class 7 Agricultural Science Chapter 1 Mrida Vinyas

मृदा विन्यास

अभ्यास

Question 1. सही उत्तर पर सहीं (√) का चिहून लगाइये
(i) मृदा कणों का आकार होता है-
(क) गोलाकार (√)
(ख) लंबाकोर
(ग) वर्गाकार
(घ) चौड़ा
Answer: (क) गोलाकार
In simple words: Soil particles often have a round, spherical shape. This shape is common for individual soil grains.

🎯 Exam Tip: Recognizing the shape of soil particles helps understand how they fit together and affect soil properties.

Question 1. (continued)
(ii) केशिका जल होता है-
(क) बहता हुआ जल
(ख) स्थिर जल
(ग) गुरुत्वाकर्षण बल के विरुद्ध मिट्टी में पाए जाने वाला जल (√)
(घ) तालाब का जल
Answer: (ग) गुरुत्वाकर्षण बल के विरुद्ध मिट्टी में पाए जाने वाला जल
In simple words: Capillary water is the water that stays in the soil, held against gravity, and is available for plants to use. It fills the small spaces between soil particles.

🎯 Exam Tip: Capillary water is vital for plants, so always remember it's the water held by soil particles against gravity.

Question 1. (continued)
(iii) मृदा जल संरक्षण करते हैं-
(क) कुआँ खोदकर
(ख) तालाब खोदकर
(ग) नाला बनाकर ।
(घ) जुताई के बाद पाटा लगाकर (√)
Answer: (घ) जुताई के बाद पाटा लगाकर
In simple words: After plowing, leveling the soil helps conserve water by keeping it from running off quickly. This practice allows water to soak into the ground.

🎯 Exam Tip: Proper plowing and leveling are simple yet effective farming techniques for soil moisture conservation.

Question 1. (continued)
(iv) दानेदार कणीय विन्यास होता है
(क) जब कण अलग-अलग होते हैं।
(ख) जब कण पानी में घुले होते हैं।
(ग) जब कण सूखकर ढेला बनाते हैं।
(घ) जब कण आपस में मिलकर एवं एक झुंड बनाकर दूसरे झुंडों को चार स्थानों पर छूते हैं। (√)
Answer: (घ) जब कण आपस में मिलकर एवं एक झुंड बनाकर दूसरे झुंडों को चार स्थानों पर छूते हैं।
In simple words: Granular soil structure is when small soil particles group together to form rounded clusters, and these clusters touch each other at four points. This structure helps with water and air flow.

🎯 Exam Tip: Remember that granular structure is excellent for soil health, promoting good aeration and water infiltration.

Question 1. (continued)
(v) तिर्यक विन्यास में प्रत्येक कण दूसरे कणों को कितने स्थानों पर छूता है।
(क) दो
(ख) चार
(ग) छः (√)
(घ) आठ
Answer: (ग) छः
In simple words: In a platy (or tabular) soil structure, each soil particle is in contact with six other particles. This specific arrangement often results in flatter, plate-like layers.

🎯 Exam Tip: Different soil structures have distinct contact points between particles, affecting soil properties like drainage and root penetration.

Question 2. रिक्त स्थानों की पूर्ति कीजिए-
Answer:
(i) स्तम्भी विन्यास में मृदा कण एक-दूसरे से **चार** स्थानों पर मिलते हैं। In columnar structure, soil particles touch each other at four points, which is a specific type of soil arrangement.
(ii) जब जल वाष्प में परिवर्तित हो जाता है, तो उसे **गैस** अवस्था कहते हैं। When water changes into vapor, it is called the gaseous state, due to heating and particle movement.
(iii) मृदा के खाली भाग को **रन्ध्रावकाश** कहते हैं। The empty spaces in the soil are called pore spaces, which are crucial for holding air and water.
(iv) उर्वरकों के लगातार अधिक प्रयोग से मृदा **खराब** हो जाती है। Using too many fertilizers continuously makes the soil bad, as it can harm its natural balance and fertility.
(v) पौधे **केशिका जल** को आसानी से ग्रहण करते हैं। Plants easily absorb capillary water, which is readily available to their roots and essential for growth.
In simple words: Fill-in-the-blanks cover facts about soil structure (particles touch at four points in columnar), water states (vapor is gas), soil spaces (pore space), fertilizer effects (overuse harms soil), and water types plants use (capillary water).

🎯 Exam Tip: For fill-in-the-blanks, focus on keywords and core definitions to choose the correct term. Understand why each answer fits the context.

Question 3. निम्नलिखित कथनों में सही पर सही (√) तथा गलत पर गलत (X) का चिह्न लगाइए-
Answer:
(i) तिर्यक विन्यास में मृदाकण आपस में एक-दूसरे को छः स्थानों पर छूते हैं। (√)
In platy soil structure, soil particles touch each other at six points. This statement is true, as these flat particles are often stacked in layers.
(ii) जुताई, गुडाई, निराई करके मृदा में जल संरक्षण किया जाता है। (√)
Plowing, weeding, and tilling help to conserve water in the soil. These farming practices keep the soil loose and prevent rapid water runoff.
(iii) खेत की मेड़बन्दी करके वर्षा जल को नष्ट होने से बचाया जा सकता है। (√)
Making bunds (small earthen barriers) around fields can prevent rainwater from being wasted. These bunds hold water in the field, allowing it to soak into the soil over time.
(iv) जल एक अच्छा विलायक है। (√)
Water is a good solvent. This means many substances can dissolve in water, which is why it's essential for biological processes.
(v) कार्बनिक पदार्थ का मृदा विन्यास पर कोई प्रभाव नहीं पड़ता है। (X)
Organic matter does not affect soil structure. This statement is false because organic matter greatly improves soil structure, making it more stable and fertile.
(vi) रन्ध्रावकाश पौधों को समुचित पोषक तत्व पहुँचाने में सहायता करता है। (√)
Pore spaces help plants get enough nutrients. These spaces allow air and water, which carry dissolved nutrients, to reach plant roots easily.
(vii) रूफ-टॉप जल संचय वर्षा जल संचय की विधि नहीं है। (X)
Rooftop rainwater harvesting is not a method of collecting rainwater. This statement is false; rooftop harvesting is a very effective and common way to collect and store rainwater.
In simple words: True statements include: platy structure has 6 contact points, tilling conserves water, bunding fields saves rainwater, water is a good solvent, and pore spaces help plants get nutrients. False statements include: organic matter has no effect on soil structure (it does) and rooftop harvesting is not a water collection method (it is).

🎯 Exam Tip: Read each true/false statement carefully. For false statements, mentally correct them to understand why they are wrong.

Question 4. निम्नलिखित में स्तम्भ 'क' का स्तम्भ 'ख' से सुमेल कीजिए (सुमेल करके)-
Answer:
Here are the correct matches between Column 'A' and Column 'B':
**स्तम्भ 'क' (Column A)                 स्तम्भ 'ख' (Column B)**
मृदाकण सजावट (Soil particle arrangement)                    मृदा विन्यास (Soil structure)
स्तम्भी विन्यास (Columnar structure)                               कणों का चार स्थानों पर छूना (Particles touch at four points)
दानेदार कणीय विन्यास (Granular particle structure)      कणों का आपस में मिलकर झुंड बनाना (Particles form clumps together)
मृदा में खाली जगह (Empty space in soil)                           रन्ध्रावकाश (Pore space)
भूमि में नमी संरक्षण (Moisture conservation in land)         जुताई (Plowing)
गुरुत्वाकर्षण बल के विरुद्ध मृदाजल (Soil water against gravity)      केशिकाजल (Capillary water)
कृषि कार्य (Agricultural work)                                              पाटा लगाना (Leveling)
In simple words: This matching exercise connects terms related to soil structure, water types, and farming practices. For example, how soil particles are arranged is soil structure, and plowing helps save moisture in the land.

🎯 Exam Tip: When matching columns, ensure you understand the definition or function of each term to correctly pair them. Look for direct relationships.

Question 5.
(i) प्रकृति में जल किन-किन रूपों में पाया जाता है?
Answer: In nature, water is found in three main forms: solid (ice or snow), liquid (water), and gas (water vapor or steam). These different states are important for various natural cycles, like the water cycle.
In simple words: Water in nature exists as ice (solid), liquid water, and vapor (gas).

🎯 Exam Tip: Always remember the three states of matter for water and be ready to provide an example for each.

Question 5. (continued)
(ii) मृदाकणों के चारों ओर महीन परत के रूप में पाए जाने वाले जल को क्या कहते हैं?
Answer: The thin layer of water found around soil particles is called hygroscopic water. This water is held very tightly by the soil particles and is generally not available for plants to use because of the strong forces binding it.
In simple words: The very thin layer of water stuck around soil particles is called hygroscopic water.

🎯 Exam Tip: Distinguish hygroscopic water from capillary water; the former is unavailable to plants due to strong forces.

Question 6. मृदा विन्यास को परिभाषित कीजिए ।
Answer: Soil structure refers to how individual soil particles (like sand, silt, and clay, which come from broken-down minerals and rocks) are arranged and grouped together. These particles often form spherical shapes and are organized in specific patterns within the soil. This overall arrangement greatly influences how air and water move through the soil, which is crucial for plant growth.
In simple words: Soil structure describes how tiny soil pieces fit together. It shows if they are loose or form groups, which affects how water and air pass through the soil.

🎯 Exam Tip: When defining soil structure, remember to mention both the arrangement of particles and its impact on water and air movement.

Question 7. मृदा विन्यास कितने प्रकार का होता है? वर्णन कीजिए ।
Answer: Soil structure is primarily of four types:
1. **Columnar Structure:** This type of soil is loose and soft. It is considered excellent and fertile for agriculture due to its good workability.
2. **Platy (or Tabular) Structure:** In this structure, the soil particles are arranged in flat, plate-like layers. It tends to have fewer pore spaces, which can lead to lower crop yields as water and roots face resistance.
3. **Massive (or Compact) Structure:** This structure is very dense. It makes it difficult for both water and air to move through the soil, hindering plant root growth and nutrient uptake.
4. **Granular (or Crumb) Structure:** This is considered the best type of soil structure for agriculture. It is commonly found in loamy and clay-loamy soils. Granular structure allows good drainage, aeration, and root penetration, promoting healthy plant development.
In simple words: There are four main types of soil structure: columnar, platy, massive, and granular. Granular is the best because it lets water and air move freely, helping plants grow well.

🎯 Exam Tip: When describing soil structures, mention their key characteristics and how each type affects agricultural productivity and water/air movement.

Question 8. मृदा जल को पारिभाषित करते हुए उसके विभिन्न रूपों का विस्तार से वर्णन कीजिए-
Answer: Soil water is the water held within the soil. It is essential for plant life and exists in three main forms:
1. **Gravitational Water:** After heavy rain or irrigation, when the soil's pore spaces are completely filled, the excess water that the soil cannot hold moves downwards through the soil due to Earth's gravity. This water drains away quickly and is generally unavailable to plants. It is also known as free water.
2. **Capillary Water:** This is the water that is held in the small, fine pore spaces of the soil against the force of gravity. It remains in the soil and is readily available for plants to absorb in a dissolved form. This type of water is the most important for supporting plant growth.
3. **Hygroscopic Water:** This water is held very tightly as a thin film around the surfaces of individual soil particles. It is so strongly bound to the soil that plants cannot absorb or utilize it. Even irrigation water that becomes hygroscopic is essentially unavailable for plant uptake, often draining away or remaining inaccessible.
In simple words: Soil water is found in three ways: gravitational water (which drains away quickly and plants can't use), capillary water (which stays in the soil and plants can use), and hygroscopic water (which is tightly held by soil bits and plants cannot reach).

🎯 Exam Tip: Clearly differentiate between the three types of soil water, focusing on their availability to plants and how they are held in the soil.

Question 9. वर्षा जल को नष्ट होने से बचाने के उपायों का वर्णन कीजिए ।
Answer: To prevent rainwater from being wasted and to conserve it, several effective methods can be employed:
1. **Leveling and Bunding Fields:** Making agricultural fields flat and building small earthen barriers (bunds) around them helps to stop rainwater from flowing out quickly. This allows the water to soak into the soil slowly, increasing moisture content.
2. **Deep Plowing:** Plowing the field deeply helps to loosen the soil, which in turn allows it to absorb and retain more rainwater.
3. **Contour Plowing:** Plowing across the natural slope of the land rather than up and down creates ridges that trap water. This method ensures that water stays in the field longer, allowing it to seep into the soil gradually.
4. **Building Small Dams or Check Dams:** Constructing small barriers or dams in the lower areas of sloping land can hold back flowing water. This helps to conserve water and prevent soil erosion.
5. **Afforestation (Tree Planting):** Planting trees helps to slow down the fast flow of rainwater. Tree roots also improve soil structure, increasing its water-holding capacity and reducing erosion.
6. **Deepening Lakes, Ponds, and Reservoirs:** Making natural and artificial water bodies deeper helps to collect and store a larger volume of rainwater. This stored water can then be used for irrigation during dry periods.
7. **Rooftop Water Harvesting:** In areas with less rainfall, this method involves collecting rainwater that falls on the rooftops of buildings. The collected water is then channeled into storage tanks or pits near the house for domestic uses and gardening, making efficient use of every drop.
In simple words: To save rainwater, we can flatten fields and build small walls around them, plow deeply, plow across slopes, build tiny dams, plant trees, make ponds deeper, and collect water from rooftops. All these ways help keep water from being wasted and make it useful.

🎯 Exam Tip: When listing rainwater conservation methods, provide a brief explanation for each, highlighting how it helps prevent water wastage or stores it for later use.

Question 10. निम्नलिखित वर्ग पहेली में सही शब्दों को भरिए-
Answer: Here are the correct words to fill in the crossword puzzle:
**ऊपर से नीचे की ओर (Down):**
1. केशिका जल (Capillary Water)
2. स्तम्भीविन्यास (Columnar Structure)
3. मेंड़बंदी (Bunding)
4. आर्द्रताग्राही जल (Hygroscopic Water)
**बाएँ से दाएँ (Across):**
5. रन्ध्रावकाश (Pore Space)
6. जलचक्र (Water Cycle)
7. गुरुत्वाकर्षण (Gravity)
In simple words: For the crossword, "Capillary Water" and "Columnar Structure" are examples of words going down. Words going across include "Pore Space" and "Water Cycle".

🎯 Exam Tip: For puzzles, ensure each word correctly fits its definition and direction (down or across) within the grid. Double-check spelling and length.

प्रोजेक्ट कार्य

विद्यार्थी स्वयं करें।