Foundations Of Crop Production

Drip irrigation is an efficient water delivery system that applies water directly to the roots of plants through a network of tubes, emitters, and valves. It is widely used to conserve water, improve crop yields, and prevent soil degradation.  **Statement 1 is correct:** Drip irrigation delivers water precisely at the plant's root zone, reducing the moisture available on the soil surface. Since weeds typically thrive in moist topsoil, limiting water exposure to non-target areas helps suppress their growth. This makes weed control easier compared to traditional irrigation methods like flooding or sprinklers, which wet the entire field. **Statement 2 is incorrect:** Soil salinity refers to the accumulation of salts in the soil, which can hinder plant growth. While drip irrigation helps manage water efficiently, it does not directly reduce salinity. However, it can be combined with strategic flushing techniques (applying extra water at intervals) to push salts below the root zone, preventing salt buildup in the upper soil layers. **Statement 3 is correct:** Drip irrigation releases water slowly and in a controlled manner, reducing surface runoff that can lead to soil erosion. Unlike traditional flood irrigation, which can wash away the topsoil, drip irrigation preserves soil structure and fertility, making it a sustainable choice for agriculture. Hence, the correct answer is option C.

**Statement 1 is incorrect:** High organic matter content in soil actually increases its water-holding capacity. Organic matter helps to bind soil particles together, creating pore spaces that can hold water. It acts like a sponge, absorbing and retaining moisture effectively. **Statement 2 is incorrect:** Soil plays a crucial role in the sulphur cycle. Soil contains various forms of sulfur compounds, including sulfates, which are essential nutrients for plant growth. Microorganisms in the soil participate in the transformation of sulfur compounds through processes like mineralization and immobilization. **Statement 3 is correct:** Excessive or improper irrigation practices can lead to the salinization of agricultural lands. When irrigation water contains high levels of dissolved salts, and there is inadequate drainage, these salts can accumulate in the soil over time, leading to soil salinization. This can adversely affect crop growth and productivity. Therefore, among the given statements, only statement 3 is correct.

In India, the use of carbofuran, methyl parathion, phorate and triazophos is viewed with apprehension because they are all pesticides used in agriculture. These pesticides are considered hazardous due to their potential negative impacts on human health and the environment.

**Statement 1 is correct:** Fertigation is a method of delivering fertilizers to crops through an irrigation system. It involves the precise application of water-soluble or liquid fertilizers directly to the root zone of plants during the irrigation process. This technique allows for the controlled release of nutrients, ensuring that plants receive the right amount at the right time. Fertigation allows for the control of the pH of the irrigation water, which can be adjusted to the optimal level for nutrient absorption by the plants. **Statement 2 is incorrect:** While fertigation does allow for the efficient application of many types of fertilizers, rock phosphate is not water-soluble and therefore cannot be applied efficiently through fertigation. **Statement 3 is correct:** Because fertigation delivers nutrients directly to the root zone of plants, it increases the availability of nutrients to the plants. **Statement 4 is correct:** Fertigation allows for the precise application of nutrients, which reduces the risk of nutrient leaching. Therefore, options 1, 3, and 4 are correct.

Water efficiency of a crop refers to the amount of water required for its growth and development. Among the options provided, Sugarcane requires the highest amount of water for its growth, making it the least water-efficient crop. It needs around 1800-2200 mm of water per season. On the other hand, Sunflower requires about 672.4 mm/season, Pearl Millet being a drought-tolerant crop requires around 350 mm/season, and Red gram uses about 250-400 mm/season of water. Therefore, Sugarcane is the least water-efficient crop among the given options.