Agronomy

Salinity tolerance refers to the ability of a plant to grow and complete its life cycle on a substrate that contains high concentrations of soluble salts. Green gram (Vigna radiata) is highly sensitive to salt stress, which significantly affects its growth and grain yield. Step 1: Analyze the options.
(A) Dates: Date palms are known for their high tolerance to salinity and can thrive in arid regions with salty soil.
(B) Cotton: Cotton is classified as a salt-tolerant crop, often grown in areas where other crops might fail due to soil salinity.
(C) Mustard: Mustard possesses a moderate level of tolerance to salinity compared to many pulse crops.
(D) Green gram: Pulses, in general, are sensitive to salinity. Green gram specifically is considered intolerant or highly sensitive, as even low levels of salinity can inhibit its nitrogen-fixing capabilities and overall development.
Step 2: Conclusion.
Among the given options, Green gram is the most intolerant to saline conditions. Hence, the correct answer is (D).
Final Answer:

Diara lands are flood-prone areas located in the river basins. While these areas are often fertile due to annual silt deposition, some specific zones become unfit for cultivation due to an excess of sand particles. Large deposits of coarse sand reduce the soil's water-holding capacity and nutrient retention, making it difficult for most crops to survive.
Step 1: Analyze the options.
(A) Gravel: While present in some riverbeds, gravel is less common than sand in the vast stretches of Diara floodplains.
(B) Sand: High sand content (sandy diara) leads to poor soil structure and excessive drainage, which is the primary reason for cultivation failure in these specific riverine areas.
(C) Silt: Silt is actually beneficial for agriculture; Diara lands are famous for their high silt content which usually makes them very productive.
(D) Clay: Excessive clay can cause waterlogging, but in the context of Diara areas, the "wasteland" portions are typically dominated by sand deposits left after heavy floods.
Step 2: Conclusion.
The presence of excess sand is the limiting factor for agriculture in unproductive Diara patches. Hence, the correct answer is (B).
Final Answer: