Reasons for decline in soil fertility

 Reasons for decline in soil fertility

Introduction

Soil fertility is a component of overall

soil productivity that deals with its

available nutrient status, and its ability

to provide nutrients out of its own

reserves and through external

applications for crop production.

Increasing pressure on limited agricultural land in Indiahas resulted in overuse of chemical fertilisers, excessive tillage, and lack of appropriate crop rotation.

This has resulted in soil degradation and loss of fertility,which are emerging as major challenges for the Indianfarmers.

Clearly, the pressures of constantly increasing productionhave in turn resulted in a persistent decline in soilfertility– a major challenge that Indian agriculture iscurrently facing.

With rising population, limited availability of agriculturalland, small land holdings and declining soil fertility, Indiais under serious threat of losing its food surplus status inthe near future.

According to estimates, the demand for food grains isexpected to increase from 192 million tonnes in 2000 to 355 million tonnes in 2030.

Causes of decline in soil fertility

1. Loss of top soil by erosion

2. Nutrient mining

3. Physical degradation of soil (poor structure, compaction,

crusting and waterlogging etc.

4. Decrease in organic matter content and soil bioactivity

5. Loss of nutrients through various routes

6. Soil acidification, salinization and alkalization

7. Inefficient soil management

8. Soil pollution

1. Loss of top soil by erosion

The top soil is rich in nutrients and organic

matter. Loss of the fertile topsoil components

through erosion by water and wind results in

decreased fertility.

Soil erosion is very common in many parts of

the country.

The basic causes of soil erosion are the result

of human activities such as deforestation,

overgrazing and poor soil management.

2. Nutrient mining

• Removal of more nutrients by crops than

added through manures or fertilizers is

called as nutrient mining or depletion.

•  At present, nutrient mining is a

major threat to productive

sustainable farming. It is a widespread problem in

low- and medium input

agriculture. Nutrient mining is accelerated by

imbalanced fertilization.

Agriculture and Its Evolution

 Agriculture

• Derived from Latin words
• 'Ager'- soil
• 'Cultura'- cultivation
• Agriculture is a very broad term encompassing all aspects of crop production, livestock farming, fisheries, poultry, forestry, etc.
• Science and art of cultivating crop and rearing of animals 
• Integration of crop and animal rearing
• Agriculture started with civilization of human being
• All primary necessity of human life are directly related to Agriculture
• At present agriculture are main profession and the most important human economic activity worldwide
• Plant convert the environmental inputs ( i.e., solar energy, carbon dioxide, water) into economy products (i.e., plant actually do)

The beginning

• World was formed around 4600 million years ago
• Eukaryotic life forms: 1000 million years ago 
• First hominid life forms: 4 million years ago
• Earliest man (Homo ererctus) forms: 1.5 million years ago
• Control and use fire: 500 thousand years ago
• Direct ancestor of modern man( Homo sapiens): 250 million years ago
• Modern man appear in Africa: 35000 years ago
• First human farmers: about 12000 years ago
• Modern agriculture evolution: 1950 - present

Evolution of Agriculture ~ Timeline

The most important event in history of agriculture after 7500 BC listed as:-

• 7500 BC: Conversation of crops (wheat, barley)
• 6000 BC: Domestication of cattle and pig
• 4000 BC: Cultivation of maize
• 3500 BC: Cultivation of potato
• 3400 BC: Wheel was invented 
• 3000 BC: Bronze was used to make tools
• 2900 BC: Plough was invented, Irrigation started
• 2700 BC: Silk moth domestication
• 2300 BC: Cultivation of chickpea, pea, mustard and cotton. Domestication of fowl, buffalo and elephant
• 2200 BC: Cultivation of rice in India
• 2100 BC: Cultivation of fingermillet
• 1725 BC: Cultivation of sorghum
• 1700 BC: Taming of horses
• 1500 BC: Cultivation of sugarcane and Irrigation from wells
• 1400 BC: Use of Iron
• 1500 AD: Cultivation of sweet orange, sour orange, wild brinjal, pomegranate
• 1600 AD: Introduction to several crops in India from Portugal (sweet potato,  tomato,  chillies, pumpkin, papaya, cashew nut, custard apple, groundnut,  cotton, rubber, tobacco)

Stages in Development of pre-historic Agriculture

Identification and conservation of desirable native plants

• By using various part of plants like root leaves, seeds, fruit, flower, etc. man identified the desirable plant (crop plants)
• Conserved those plants from danger

Collection and preservation of seeds

• After eating fruit threw seeds which germinated into same type of plants
• Collected seeds were grown at desirable place

Sowing of seeds

• With increase in population shortage of food was faced leading to start of sowing on the basis of climatic suitability

Tilling of land

• Seeds were damaged by birds or air or flow of water
• Loosened the soil (stone/wooden tools) and put seeds in soil

Shifting cultivation

• Enough land available for raising crops/plants
• Reduction in yield on same land 
• Shifted farming to new land

Weed control

• Unwanted plants grow with desirable plants and compete for resources
• Control of these unwanted plants (weed)  started
• Women mostly performed this work

Fallowing of land

• With rise in population people started living in groups and established villages 
• Reduction in yield on continuous raising crop plants on same soil
• Started fallowing same portion of land and tilling old fallow land

Use of domestic waste as plant nourishment

• Use of domestic waste in agriculture, good growth of crops
•  Domesticated several animals i.e., sheep, goat, cow and buffalo 
• Use of dunk, urine and animal wastes improved the soil fertility 
• Use of ashes, domestic waste, animal dung and urine and animal waste in agricultural production

Following crop rotation

• Growing cereals after legume crops gives better yield which resulted in crop rotation practice 
• Later must have known that legume fix atmospheric nitrogen

Green manuring

• Legumes must have been grown and turned into soil to improve the soil fertility

Contribution of India in Agricultural development

• Cultivation of rice
• Native of India:-  sugarcane, several legumes and tropical fruit like mango

Mohan Jodaro to Harappa territory (3000-1700 BC)

• Huge granaries 
• Main crops:- Barley, wheat, sesamum, peas, cotton, mustard, date palm and lantil 
•  Wooden plough and wheeled cart were used first time
• Ginning, spinning and weaving of cotton 
• Sling-ball for scaring birds and animals

Hindu epics

• Agriculture most important profession during this period
• Iron plough were started using
•  Main crops:- Bean, sesamum, millets, rice in Vedas
•  Buddhist period (600BC)- Importance of trees
•  Mahabharat and Ramayan (1000-500BC) 
• Irrigation from cauvery river (1AD-300AD)
• Amarkosha (Chandragupta-2  300AD) was a book mentioned in about classification of soil, land use, irrigation and manure
• Kanuj Empire of Harsha (606-647AD), during this period Fine scented rice was grown and also cultivation of pomegranate and sweet orange
• Krishi parashra (950-1100AD) was a book mentioned in about land manuring, crop rotation, irrigation, tillage, implements,  crop protection, and meteorology
• Construction of water reservoirs and irrigation channels (1336-1646AD)
•  Anantraja Sagar in Vijayanagar of AP (1337AD)

Mughal dynasty

• Gardens, flowers cultivation and provision of irrigation 
• large sum collection from peasants as peasantry (tax)

Status of Agriculture before Independence

• Arrival of Britishers in early 17th century
• Dynamic craft and cottage industries suffered due to mass production technology of British
• Modern institutions, universities, technologies, rail lines, roads, mass communication were developed
• Land ownership was given to a small group of peoples to the collect the rent from individual farmer and pay to government
• Zamindari system:-  Land ownership given to small group of people to collect the rent and pay to the Government
• Ryotwari system:-  Rural used used to collect rents directly from farmer
• Farmers had no security of land
• Irrigation scheme initiated
• Department of agriculture (1871) was created at national level
• Agriculture education facility:- Coimbatore(1878) and Pune (1890)
• Great famine (1876-77) , Famine commission appointed (1880)
• Royal agricultural society:-  Report on improvement in Indian agriculture (1891)
• IARI (1905) was setup at pusa Bihar 
• Agricultural college was set up
• Royal commission(1926)
• Department of food was created (1942)
• Grow more food Campaign,  food policy committee, Famine enquiry committee and fertilizer production program were initiated around 1945
• Research support to agriculture by creating research institution

Development of Agriculture after Independence

• Education commission (1948)
• Join Indo-American teams of 1955, 1950 and 1961
• Education commission (1964-66)
• State agriculture universities (SAUs) were established to integrate the agricultural education, research and extension activity
• At present we have 62 State agricultural universities, 5 Deemed universities and 2 Central agricultural universities, 4 Central universities with agriculture faculty
• Major areas of education started (Agriculture veterinary science, agriculture engineering, forestry, dairy technology, food technology, horticulture, fisheries, agribusiness
• ICAR:-  The Indian Council of Agricultural Research as the apex agency, is responsible  for growth and development of agricultural education and research in India
• The ICAR coordinates research in the country through its wide network of  National and Central research institutes (62), National research centre (14), National Bureaux (6), Directories project directories (14), All India coordinated research project (60), Network projects (19) and other project (10)

Modern Indian Agriculture

• Advancement of science and technology in agriculture
• Farmers adopt new technologies and techniques of agricultural production by replacing the traditional practices to harness the high level of productivity
• Self sufficient to meet the human and livestock needs and also provide sufficient raw material to industries
• Maintaining pace in agricultural production

Development leading to modernization of agriculture

Development of ideal plant types/varieties

After 1960, vast improvement in crop varieties has been made. Introduction of high yielding varieties responding to better management particularly in wheat and rice and hybrid in maize, sorghum, pearl millet, cotton and several vegetable crop has been tremendous positive change in agriculture production. Varieties resistance to many disease and insects, pests are available.

Development of improved crop production technologies

Improved production techniques for crop cultivation based on availability of various resources viz., land, water, capital and farm machineries have been developed. Improved production technologies includes selection of suitable crops/varieties, proper  land preparation, efficient sowing management (sowing time, seed rate, sowing method and plant geometry etc.), balanced nutrition, effective weed control,  aquatic water management and proper plant protection measures. Thus the new agriculture itself is an industry.

Minimum/zero tillage

Earlier it was considered that more yields are possible with more tillage, but now this idea has been changed. Now growers try to utilize the rich nutrition for upper soil surface and soil moisture more efficiently by minimising or not doing the tailors operations.

Intensive cropping

In the past, monocropping and double cropping under rainfed farming were considered ideal for crop production. Now due to availability of early maturing high yielding varieties and efficient soil moisture conservation techniques, several double cropping system has been evolved. Growing of three or more crops in a succession even without giving the rest to land became quit feasible to raise the returns per unit area and time. Many studies found that, intensive cropping system has no adverse effects on soil properties.

Dryland agriculture

In the areas where evapo-transpiration is greater than precipitation, growing of crops were risky but not improved cultivation technology for growing suitable crop has been developed. Now it is said, that soils of dry farming reasons are more hungry and thirsty.

Use of problematic and waste land in agriculture

This problematic soil like saline, alkaline,  acidic, flood prone, desert and other soils unsuitable for agricultural use are being reclaimed with suitable scientific technologies for their effective use in agriculture.

Maintenance of soil-health

It is well known that soil is a medium for plant growth to give ultimate yields. Hence,   any operation on the soil for agriculture viz., tillage, manuring, fertilizer application, irrigation, drainage, wedding, interculture practices and use of agrochemical may be done taking due to consideration about their influence on soil properties.

The old philosophy of Indian farming is getting changed and modern improved techniques for growing crops are being adopted.

A slow and gradual process (conclusion)

• Community living increase man's dependence on food
• Hunter-gathered status no longer sufficient
• Survival and self preservation were major challenges
• Increasing population
• Man learn to grow crops