To answer this question, you need to understand the concept of materials of biological origin used to maintain and improve soil fertility.
Option A) Green manure - This option is correct. Green manure refers to the practice of growing and incorporating specific crops or plants into the soil to improve its fertility. These crops or plants are usually legumes, grasses, or cover crops that are grown and then plowed under, adding organic matter, nitrogen, and other nutrients to the soil.
Option B) Biofertilizers - This option is correct. Biofertilizers are substances that contain living microorganisms, such as bacteria, fungi, or algae, that help improve soil fertility by enhancing nutrient availability and nutrient cycling in the soil. These microorganisms have the ability to fix atmospheric nitrogen, solubilize phosphorus, and mobilize other nutrients, making them available to plants.
Option C) Bioinsecticides - This option is incorrect. Bioinsecticides are substances derived from biological sources that are used to control insect pests. While they may have some indirect effects on soil fertility, their primary purpose is pest control, not soil fertility improvement.
Option D) Both A and B - This option is correct. Both green manure and biofertilizers are materials of biological origin commonly used to maintain and improve soil fertility.
Therefore, the correct answer is D) both A and B. These options are correct because green manure and biofertilizers are commonly used to maintain and improve soil fertility by adding organic matter, nutrients, and beneficial microorganisms to the soil.