eChapters

7.1 Introduction

The current atmospheric CO₂ concentration is the highest during last 650,000 to 800,000 years (Luthi et al., 2008), and also probably in the last 20 million years (Pearson and Palmer, 2000). Since last two decades, it is increasing at a rate of about 2 ppm/yr with the current concentration of 389 ppm in 2010 (WMO, 2011). The current trend of energy use based on fossil fuel consumption may raise it to 900 - 1100 ppmby the end of 21^st century (Kiehl, 2011).

Large parts of the country perennially reel under recurring drought. Over 68% of India is vulnerable to drought. The ‘chronically drought-prone areas’ – around 33%, receive less than 750 mm of rainfall, while 35%, classified as ‘drought-prone’ receive rainfall of 750-1,125 mm. The drought-prone areas of the country are confined to peninsular and western India – primarily arid, semi-arid and sub-humid regions. Approximately 218.1 thousand square kilometers of land in India under sub-tropical semi-arid and arid conditions are spread over the states of Rajasthan, Gujarat, Haryana and Madhya Pradesh (Anonymous, 1974). Agriculture is predominantly rainfed and the region is drought-prone. Less than 23% of land is irrigated. Forest cover is <5% and waste and fallow areas occupy 42% of the land.

Millets are highly nutritious and play a significant role in many people’s diets around the world. They have traditionally been transformed into a range of products through fermentation and malting for centuries. In the era of sustainable development, we still lag in using millets as a primary source of nutrition even after knowing that they are rich in terms of nutrition and other essential elements as compared to cereals. Today we have lots of information regarding different millets; nutrition content, methods of preservation, fermentation, malting, its products etc. Foods made from millet are regarded as potential prebiotics because they can improve the availability or functionality of probiotics, which has major positive effects on health. Foods have been fermented in order to enhance their flavor, texture and palatability. Although fermentation can result in a variety of products, the most prevalent ones are ethanol, lactic acid, carbon dioxide and hydrogen gas (H2 ). Commercial applications for these materials include use in food, vitamins, medications and industrial chemicals. Additionally, fermentation increases the amount of protein present, improves the accessibility of carbohydrates and reduces antinutritional components like tannin and phytic acid. Even though it has some drawbacks, such as the potential for contamination with dangerous microbes, fermentation technology is proven to enhance the nutritional quality of food products. This chapter covers the millet fermentation technology’s effects on the nutritional composition of the millets, contemporary developments in fermented millet-based products and technological improvements examined in the millet fermentation technology.

Fig 8.1: A scheme for fertigation program working with automation

In modern farming with fertigation machines (NutriCare) and automated drip irrigation systems, fertigation set up schemes like the above are put into practice. This scheme will stream line the installation, operation and monitoring of the entire process. An informed grower would be able to control crop performance more precisely and achieve his objectives.

The crop growing environment, both soil/media and aerial are controlled in green house. Therefore, the movement of water (liquid and vapour) and minerals (nutrient ions) follow a different pattern altogether. This factor should be considered while preparing the fertigation program. This becomes all the more different if soil-less rooting media is used.

Table 7.1: Differences in Nutrient uptake in open field and Protected (GH) conditions.

A. CEREALS

1. Rice (Oryza sativa)

RD 60:20:20 kg/acre NPK

(Recommended by TNAU)

SUMMARY

Fertigation is the injection of concentrated soluble nutrients into irrigation water to enhance crop production. It is used extensively in commercial agriculture and horticulture. In combination with micro-irrigation (drip irrigation), this technique forms an efficient method for precisely applying nutrients close to the crop root zone, especially when a polyethylene mulch is used. Fertigation is used to spoon feed additional nutrients or correct nutrient deficiencies detected in plant tissue analysis and usually practiced with high value crops such as vegetables, turf, fruit trees, and ornamentals. Water supply for fertigation kept separate from domestic water supply to avoid contamination. Fertilizing fruit and vegetable crops requires a delicate balance between yield, quality, and environmental impact. Fertigation increases response to nitrogen (N) and provides greater opportunity to control rates to optimum levels to the root zone. Providing nutrients through the irrigation system enables more flexibility in a fertilizer program. Several types of irrigation systems are available for use in crop production. For any system used, approved backflow control valves and interlock devices are necessary to prevent accidental contamination of the water source due to irrigation system failure or shutdown.

The Fertilizer (Control) Order

The Fertilizer (Control) Order (FCO) is a set of legally enforceable executive orders issued by the Govt. of India under the Essential Commodities Act, 1955 passed by the Parliament. This order came into force in 1957, essentially to regulate the sale, price and quality of fertilizers in India. Amendments are made from time to time as per the exigencies and need of the hour and therefore a large number of amendments were made over a period of time. Consequently, after an overall review of the various provisions of the order, a revised Fertilizer (Control) Order 1985, was issued, which came into effect on September 25, 1985. The FCO consists of five Schedules comprising of different activities as mentioned in Figure 8.1, besides forms of registrations and appendices.

Schedule I comprises Part A and B. While Part A contains the specifications of different fertilizers (e.g. minimum nutrient content, maximum moisture content, range of physical parameters, maximum levels of impurities/ contaminants, etc.), that can be marketed in India (no material not performs the specifications as in the FCO cannot be sold as fertilizer), Part B lists the tolerance limits in plant nutrients and physical parameters for various fertilizers. Schedule II encompasses again two parts, with Part A describing the procedures for drawal of samples of fertilizers, and Part B describing detailed methods of analysis of fertilizers.

Schedule III encompasses four parts namely, Part-A, Part-B, Part-C and Part-D. While Part-A contains specifications of different biofertilizers, Part-B contains tolerance limits of biofertilizers, Part-C describes the procedures for drawal of sample of biofertilizers, Part-D describes the methods of analysis of biofertilizers. Schedule IV also encompasses four parts. Part-A contains specifications of organic fertilizers, Part-B contains tolerance limits of organic fertilizers, Part-C describes the procedures for drawal of sample of organic fertilizers, and Part-D describes the methods of analysis of organic fertilizers. Schedule V also contains of four parts. Part-A contains specifications of non-edible de-oiled cake fertilizers, Part-B contains tolerance limits of non-edible de-oiled cake fertilizers, Part-C describes the procedures for drawal of sample of non-edible de-oiled cake fertilizers, and Part-D describes the methods of analysis of non-edible de-oiled cake fertilizers.

Introduction

Fertilization is the application of fertilizer for the benefit of the crops. It may be traditional broadcasting or fertigation. In broadcasting method the fertilizer is applied in concentrated granular form. The size of the granules ranges from granular dust to pellet size. These solid fertilizers get dissolved by the rain or irrigated water to leach down the plat root zone. This method results uneven nutrient delivery due to uneven dissolving the fertilizer granules. It may cause burning of plant leaves and root system due to uneven and uncontrolled release of nutrients. Dry fertilizers can volatilize and release gases which may damage or burn the nearby foliage. Availability of fertilizer to the plant root zone largely depends on the temperature and availability of water to dissolve the fertilizers.

In fertigation liquid or water-soluble fertilizer, soil amendments or other products required by the plants is either sprayed on to the plant material or applied to the plant bottom with irrigation water. Foliar application provides high rate of absorption of fertilizer through the leaf/stalk/branch structures of plants. Ground application also provides good consistency in making its way to root zone and plant absorption. Thus, the fertigation provides benefit of increased nutrient absorption; decrease water needs, and reduce the fertilizer and chemical use (Anonyms, 2005).

Fertilizer (Control) Order, 1985 which is administered by Deptt.of Agriculture Cooperation, Govt. of India has been issued under the Essential Commodities Act, 1955. The FCO lays, down as to what substances qualify for use as fertilizers in the soil, product-wise specifications, methods for sampling and analysis of fertilizers, procedure for obtaining license/registration as manufacture/dealer in fertilizers and conditions to be fulfilled for trading thereof, etc.

Fertilizers are required where soils are deficient in plant food elements. When land is planted to crops over a long period of time, the plant food elements slowly get reduced and productivity of crop goes down. Sandy soil looses plant food elements rapidly because heavy rainfall or application of irrigation water leaches these elements out from the soil. Adding chemical fertilizer increases fertility of soil. Principally nitrogen, phosphorous and potassium are added to the soil to promote greater yields. Uniform distribution and proper placement of fertilizer in the soil have become increasingly important factor in providing maximum crop response at minimum cost. Placing the fertilizer near the seeds at the time of sowing results in more effective utilization of nutrients. In the row crops side dressing of fertilizer is done which has immediate benefit when placed in the moist soil within the root zone.

Knowledge of fertilizer dose, selection of fertilizer sources, time and method of application is essential for achieving efficient use of fertilizers and profitable yield.

A. Fertilizer Dose

Fertilizer dose for crops is determined based on the field experimentation. It varies with the crops and varieties, initial fertility of the soil, soil properties, cropping system, climate, season, rainfed or irrigated crop, expected yield etc. Fertilizer dose for rainfedcrops (Kg/ha)

Fertilizer N has been the key input in increasing cereal production throughout the world. In India, it made possible to achieve the yield potential of high-yielding dwarf varieties of wheat that led to ‘Green Revolution in 1968’. Nitrogen fertilization also increases protein content in wheat grains (Rajeswara Rao and Prasad, 1987) and leads to increased production of proteins in cereals (Prasad and Shivay, 2015). Cereal production in India increased from 42.4 million tonnes (Mt) in 1950–51 to 259.6 Mt in 2017–18, while fertilizer N application increased from 0.05 Mt to 16.96 Mt. However, the average agronomic ef?ciency of N (AEn) in India for cereals is only 9.5 kg grain kg–1 N (Sharma and Batra, 2011) as compared to global average of 24 kg grain kg–1 N for maize, 22 kg grain kg–1 N for rice and 18 kg grain kg–1 N for wheat (Ladha et al., 2005). Besides this, more disturbing is the fact that in irrigated areas the AEn declined from 13.4 to 3.4 kg grain kg–1 N during 1970–2005 (Biswas and Sharma, 2006). This is due to poor N management. Bulk of fertilizer N is applied broadcast on surface in most crops.

Fertilizers are applied to supplement nutrient requirement of the crop. It should not be looked as a substitute to organic sources. After determination of nutrient requirement of a crop fora given yield and contribution of nutrients from different sources, articularly, from the soil source, it is necessary to supplement the balance from the inorganic sources. These are determined by field experimentation supplemented by pot-culture, laboratory and green housestudies, if necessary. When a fertilizer is applied all of its nutrient (s) are not absorbed by the crop. The interactions between soil-crop-season and other factors are quite significant. Only a fraction of the nutrient(s) is utilized by the crop.

Plant requires food or nutrients or elements for its growth and development which are absorbed through soil. Adequate supply of plant nutrients is important to ensure efficient crop production. Plant nutrients are essentially applied through manures and fertilizers. Application of manures and fertilizers to the soil is one of the important factors which help in increasing the crop yield and to maintain the soil fertility. 
Manures
Manures are plant and animal wastes that are used as source of plant nutrients. They release nutrient after their decomposition. These are relatively bulky materials, such as animal or green manures, which are added mainly to improve the physical condition of the soil, to replenish and keep up its humus status, to maintain the optimum conditions for the activities of soil micro-organisms and make good a small part of the plant nutrients removed by crops or otherwise lost through leaching and soil erosion.

Any material of natural or synthetic origin added to the soil to supply one or more plant nutrients.

10.1. Classification of fertilizers

10.1.1. Straight fertilizers

Supply only one primary plant nutrient, namely nitrogen or phosphorus or potassium.

Eg. Urea, ammonium sulphate, potassium chloride and potassium sulphate.

Fertilizer

Fertilizers are defined as materials having definite chemical composition with a high analytical value that supply essential plant nutrients in available form. They are usually manufactured by industries and sold with a trade name. They are commonly synthetic in nature and also called as chemical fertilizers/inorganic fertilizers/commercial fertilizers other than lime and gypsum. Most of the chemical fertilizers are inorganic in nature.

Organic Fertilizers and Manures

Farmers have been using organic waste as fertilizers for a very long time. As previously mentioned, the application of O.M. to a soil can have number of beneficial effects on soil structure, C.E.C. and microbial activity. However, organic manures mainly originate from the waste products of animal and plant production and although rich in carbon compounds, they are usually relatively poor in available plant nutrients.

The nutrient content of organic manures varies widely depending on their source and moisture content. Farm yard manure (F.Y.M.) is one of the most common organic fertilizers used. Others are concentrated animal manures, and crop residues such as straw.