Anabaena azollae, a cyanobacterium that lives in symbiotic association with the free-floating water fern Azolla. Anabaena azollae can grow Photo-autotrophically and fixes atmospheric nitrogen. The inoculation of cyanobacteria in rice crops significantly influences the growth of rice crop by secretion of ammonia in floodwater.

Quality breeds are the organism with improved quality or desired quality. It can be done by the breeding process like hybridization. The introduction of desired gene produce higher yields in a shorter time.

Peanut is grown mostly in five states namely Andhra Pradesh, Gujarat, Tamil Nadu, Karnataka, and Maharashtra, and together they account for about 90 percent of the crop's total area. Two of these states (Andhra Pradesh and Gujarat) account for more than half of the cultivated area.

The process of growing of grass or legumes in rotation with grain or tilled crops as a soil conservation method is called Ley farming

Crop rotation is the practice of growing of different types of crops in alternate season. The cash crops grown in one season is replaced by leguminous plants in the other season. The nutrients which are used up by the previous crops are regained by the second crops. So, crop rotation maintains soil fertility and prevents soil erosion.

Monoculture is the agricultural practice of producing or growing a single crop, plant, or livestock species, variety, or breed in a field or farming system for a time.

The practice of growing a series of different types of crops in the same area in sequenced seasons is called crop rotation.
The advantages of crop rotation are:-
1) It helps in reducing soil erosion.

Although the high yielding variety of seeds gave a huge amount of production, it has some disadvantages also. They require a lot of water in the field which leads to the decreasing water table. Also, the HYV seeds required higher production cost in terms of irrigation equipment. It also has an adverse effect on the environment, as HVY seeds require more fertilizer to be added to the soil for better production, which decreases the fertility of the soil.

• If the deforested forest area is replaced with only one species of trees and all other vegetation is prevented from growing back then, a monoculture forest similar to agricultural crops will be the result.
• However, the reforestation involves planting of different lots of seed of seedlings taken from the area, often of multiple species.
  
• In those areas natural regeneration of a wide variety of plant and animal species that can occur.
  

Total dry matter and yield of maize, corn and red gram planted in soil have shown an increase in the soil fertility. Maize and corn not known to fix atmospheric nitrogen. Spotted bollworm affect the cotton plants and the gram, maize and cotton do not affect the pathogenesis. 

Crop rotation is the practice of growing a series of dissimilar or different types of crops in the same area in sequenced reasons. It is done so that the soil of farms is not used for only one set of nutrients. It helps in reducing soil erosion and increases siol fertility and crop yeild.

Since a certain amount of food materials (including the sugar) is diverted for flowering, it is profitable to harvest the sugarcane crop before the initiation of flowering to obtain the maximum sugar content.

Crop rotation is the process of successive growing of crop in the same field. This helps in increasing the fertility of the soil. Helps in a good production of the crop. It decreases the population of pests. It also reduces soil erosion.

Rotation of crops improves the fertility of the soil and hence, brings about an increase in the production of food grains. It helps in saving on nitrogenous fertilizers, because leguminous plants grown during the rotation of crops can fix atmospheric nitrogen in the soil with the help of nitrogen fixing bacteria. Rotation of crops help in weed control and pest control. Crop rotation adds diversity to an operation. 

The method of growing two or more crops simultaneously on same piece of land is called mixed cropping or inter-cropping. This method helps in improving the fertility of soil.

Crop rotation is the process of planting different crops one after another in the same field. Crop rotation increases the fertility of soil and increases the production of crop. High yielding of variety of crops also increases the production of crops.

Explanation: Alley Cropping is planting rows of trees at wide spacings with a companion crop grown in the alleyways between the rows. Alley cropping can diversify farm income, improve crop production and provide protection and conservation benefits to crops.

When there is excessive use of chemical fertilizers and pesticides, the chemical salts accumulate in the soil and affect the quality and fertility of the soil. 

Crop rotation is a pattern of growing different types of crops in the same area. This method helps in the replenishment of nutrients by the regular succession of crops over the same field and enhances the health of crops. It minimizes the use of nitrogenous fertilizers. The nutrient quality of the soil can be maintained. There is no effect on the weeds and pests. 

(c) If the same crop is grown year after year, fertility of soil is lost due to utilization of same minerals again and again. Soil fertility is usually maintained in the field by rotation of crops i.e., a crop is alternated by a leguminous crop.

Crop rotation is the practice of growing of different crops in succession on a piece of land to avoid depletion of  a particular type of nutrient from the soil and to control the weeds , pests  & diseases . Other main reason of crop rotation is to give the soil the time to regain it's fertility 

Crop rotation helps in increase in soil fertility. It is the process of growing a series of different crops in the same area in sequenced seasons. It also helps in reducing soil erosion and increasing in crop yield.

Crop rotation is the practice of growing a series of dissimilar or different types of crops in the same area in during different seasons. It is done so that the soil is not depleted of a particular type of  nutrients. It helps in reducing soil erosion and increases soil fertility and crop yield. 

The particular type of plants requires certain set of nutrients. For example, sugarcane requires a large amount of nitrogen. Also, some plants render the soil with some nutrients. For example, leguminous plants make soil nitrogen rich. 
If crop rotation is carried out then the soil will not deplete with certain nutrients. Hence, growing different crops in different seasons in the same field will be beneficial for economy as well as for soil quality too.

The Sundarbans is a mangrove zone in the delta shaped by the juncture of Ganges, In spite of safeguarding duties from the two Governments, the Sunderbans are under danger from both normal and human-made causes.

Mixed cropping is a type of cultivation in which two types of crops are grown at a time and in the same piece of land. It is a form of polyculture. The characteristic of mixed cropping is balancing the nutrient level on soil, suppression of weed and insect pests, minimize the risk of crop failure etc.

Gundhi bug is a pest of rice. Its a small insect which attacks the ripening rice grains and make wither away. It sucks the milk from developing grains and stem in early stage of grain formation which causes foul smell in the field.

The method of growing different crops alternatively on same piece of land is called rotation cropping. This helps in maintaining or improving the fertility of soil.