A
SEMINAR PAPER
ON
PROSPECT OF INTEGRATED NUTRIENT MANAGEMENT IN AGRICULTURE
BY
ADELAKUN EMMANUEL OLUWAGBENGA.
CSP/07/9943
SUMMITTED TO
DEPARTMENT OF CROP, SOIL AND PEST MANAGEMENT.
SCHOOL OF AGRICULTURE AND AGRICULTURAL TECHNOLOGY,
FEDERAL UNVERSITY OF TECHNOLOGY AKURE
IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE AWARD OF BACHELOR OF AGRICULTURE TECHNOLOGY

APRIL, 2013.

CERTIFICATION
This seminar report has been read and approved as meeting the requirement for the award of B.Tech in Crop, soil and pest management.

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Student’s supervisor Date
Dr. Awodun

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Head of Department Date

TABLE OF CONTENT
Certification
Table of content
PREFACE
CHAPTER ONE
1.0 INTEGRATED NUTRIENT MANAGEMENT (I N M)
1.1 GOALS OF INTEGRATED NUTRIENT MANAGEMENT INM
1.2 PLANT NUTRIENT APPLICATION
1.3 ADVANTAGES OF INM
1.4 CONCEPTS
1.5 DETERMINANTS

CHAPTER TWO
2.0 THE PLANT NUTRIENT BALANCE SYSTEM
2.1 COMPONENTS OF INTEGRATED NUTRIENT SYSTEM
2.1.1 ORGANIC MANURES
2.1.2 LEGUME PLANTING
2.1.3 BIO-FERTILIZERS
2.2 ESSENTIAL NUTRIENTS
2.3 SOIL CHARACTERISTICS
2.4 PLANT NEEDS

CHAPTER THREE
3.0 NUTRIENT CYCLE
3.1 NUTRIENT CONSERVATION AND UPTAKE
3.2 CONCLUSION
REFERENCE

Preface
Plants require from the soil macro nutrients like nitrogen, phosphorus and potassium in large amounts which normally the organic manures are not able to supply in sufficiency. At the same time the NPK (Nitrogen, Phosphorus and Potassium) and other common fertilizers are not able to pro- vide the essential micro nutrients and other macro nutrients. Hence, we need an integrated approach to the supply of plant nutrients.

1.0 INTEGRATED NUTRIENT MANAGEMENT (I N M)
Integrated Nutrient Management refers to the maintenance of soil fertility and of plant nutrient supply at an optimum level for sustaining the desired productivity through optimization of the benefits from all possible sources of organic, inorganic and biological components in an integrated manner. Soil fertility is a dynamic property, which varies with inherent status of soil, crops, cropping intensity, and input use. More than 50% of our cultivated soil contains organic matter below the critical level. Annual depletion of plant nutrients in the intensively cropped area ranges from 180- to more than 250 kg/ha (Mollah et al., 2008). High and medium highland comprising 60% of total cultivated land, which in most cases deficient in essential nutrients, such as nitrogen, phosphorus, potassium, and sulphur. The low organic matter content, higher cropping intensity, improper cropping sequence, and faulty management practices are the major causes of depletion of soil fertility.
A crop production system with high yield targets cannot be sustainable unless balanced nutrient inputs are supplied to soil against nutrient removable crops (Bhuiyan et al.1991). Sequential cropping ensures maximization of efficient use of moisture and nutrients from soil. Integrated nutrient management for prevailing cropping systems appears to be one of the effective ways to meet the economical nutrition requirement of crop. Use of fertilizer is an essential component of modern farming with about 50% of the world crop production (Pradhan, 1992).

1.1 Goal of Integrated Nutrient Management INM
Sustainable agricultural production incorporates the idea that natural resources should be used to generate increased output and incomes, especially for low-income groups, without depleting the natural resource base. In this context, INM maintains soils as storehouses of plant nutrients that are essential for vegetative growth. INM’s goal is to integrate the use of all natural and man-made sources of plant nutrients, so that crop productivity increases in an efficient and environmentally benign manner, without sacrificing soil productivity of future generations. INM relies on a number of factors, including appropriate nutrient application and conservation and the transfer of knowledge about INM practices to farmers and researchers.

1.2 Plant Nutrient Application
Balanced application of appropriate fertilizers is a major component of INM. Fertilizers need to be applied at the level required for optimal crop growth based on crop requirements and agroclimatic considerations. At the same time, negative externalities should be minimized. Overapplication of fertilizers, while inexpensive for some farmers in developed countries, induces neither substantially greater crop nutrient uptake nor significantly higher yields (Smaling and Braun 1996). Rather, excessive nutrient applications are economically wasteful and can damage the environment. Under-application, on the other hand, can retard crop growth and lower yields in the short term, and in the long term jeopardize sustainability through soil mining and erosion. The wrong kind of nutrient application can be wasteful as well. In Ngados, East Java, for example, the application of more than 1,000 kilograms per hectare of chemical fertilizer could not prevent potato crop yields from declining. Yields on these fields decreased more than 50 percent in comparison with yields on fields where improved soil management techniques were used and green manure was applied (Conway and Barbier 1990). The correction of nutrient imbalances can have a dramatic effect on yields. In Kenya the application of nitrogenous fertilizer on nitrogen-poor soils increased maize yields from 4.5 to 6.3 tons per hectare, while application of less appropriate phosphate fertilizers increased yields to only 4.7 tons per hectare
(Smaling and Braun 1996). Balanced fertilization should also include secondary nutrients and micronutrients, both of which are often most readily available from organic fertilizers such as animal and green manures.
Lastly, balance is necessary for sustainability over time. Even annual field applications of NP and NPK fertilizers were insufficient to sustain yields over the long term. Only when both lime and NPK fertilizer were applied did yields increase and fields remain productive despite continuous cultivation (Saxena 1995).
Coupled with other complementary measures, effective nutrient and soil management can help to reclaim degraded lands for long-term use in some cases. Heavy fertilizer applications on moderately degraded soil can not only replenish nutrients, but can produce about 7 tons per hectare of maize and about 6 tons per hectare of grain straw, which long-term studies in Iowa have shown can increase organic matter content in the soil (Ange 1993). Experiments in Ghana and Niger have demonstrated that by increasing the longevity and productivity of suitable agricultural land, the application of inorganic and organic fertilizer reduces the need to cultivate unsustainable and fragile marginal lands (Vlek 1990).

1.3 Advantages of INM 1. Enhances the availability of applied as well as native soil nutrients 2. Synchronizes the nutrient demand of the crop with nutrient supply from native and applied sources. 3. Provides balanced nutrition to crops and minimizes the antagonistic effects resulting from hidden deficiencies and nutrient imbalance. 4. Improves and sustains the physical, chemical and biological functioning of soil. 5. Minimizes the deterioration of soil, water and ecosystem by promoting carbon sequestration, reducing nutrient losses to ground and surface water bodies and to atmosphere
1.4 Concepts 1. Regulated nutrient supply for optimum crop growth and higher productivity. 2. Improvement and maintenance of soil fertility. 3. Zero adverse impact on agro – ecosystem quality by balanced fertilization of organic manures, inorganic fertilizers and bio- inoculant
1.5 Determinants 1. Nutrient requirement of cropping system as a whole. 2. Soil fertility status and special management needs to overcome soil problems, if any 3. Local availability of nutrients resources (organic, inorganic and biological sources) 4. Economic conditions of farmers and profitability of proposed INM option. 5. Social acceptability. 6. Ecological considerations. 7. Impact on the environment

CHAPTER TWO

2.0 THE PLANT NUTRIENT BALANCE

THE PLANT NUTRIENT BALANCE SYSTEM

PLANT Mineral fertilizers harvested crop part

Organic manures crop residue

Atmospheric decomposition leaching

Biological nitrogen fixation gaseous losses

Sedimentation water erosion

2.1 Components of Integrated Nutrient System
Nutrient can be supplied through fertilizers and manures. But manures contain very less percentage of major macro nutrients such as nitrogen, phosphorus and potassium com- pared to fertilizers. They will not be able to meet the nutrient requirement of the crops, when applied alone. So we cannot totally depend on the manure and they should be integrated with the commercial fertilizers for fulfilling the needed quantities by plants. This integrated approach not only meet the requirement but also adds organic matter to the soil which acts as a buffer in maintaining the soil environment and thus the healthy growth of the plants. The major components that can be used in the integrated nutrient management are: organic manures, legume planting, bio-fertilizers and others residues and biproducts.

2.1.1 Organic manures
Organic manures are available in the form of green and dry plant residues fresh animal wastes, decomposed materials of plant and animal origin and biologically active preparations. When added to soil they undergo microbial decomposition. In this process, the nutrients held in organic combinations are slowly released in available forms besides improving the availability of nutrient elements present in the soil. They also promote the microbial and soil enzyme activities.

i. Farm yard manure
This manure is produced in the farm mainly with animal excreta. It is made up of the excreta of farm animals the litter or bedding provided for them and miscellaneous farm and house hold wastes. Cattle dung, excreta of other animals like sheep, horses, goats, poultry, etc. are collected and can be utilized as a manure. Litter is a bedding material that is spread in animal houses and the urine get absorbed into the bedding material. Straw, sawdust, peat, dry leaves etc are used as bedding materials.
Cattle are the main livestock maintained by the farmers in the country and the manure produced in farms may appropriately be called as cattle manure. It can be collected and can be made into manure by three main systems, namely dry earth system, byre and pit system and loose box system.
In dry earth system, dry loose loamy soil of 15 cms thickness is spread on the floor of the cattle shed. The urine soaked earth along with dung is removed everyday and stored in the manure pit.
In byre and pit system, cement or stone floor of the cattle shed is gently sloped towards manure pit by channels that will lead the urine into the pit.
In the loose box system separate pits are made and spread with a layer of straw. Animals are tethered there for dunging. Dung is not removed daily but spread on the straw. The urine is absorbed by the straw. Another layer of straw can be spread and let the animal dung and urinate on it. This process can be continued till the pit is full (may be in six months) and decomposed material can be directly taken to the field for use. ii. Composts
All organic farm wastes, stubbles of crops waste straw, sweepings, threshing floor collection, dry weeds etc. may all be collected and used for augumenting the organic matter supplies they cannot be used directly as manure in most cases. They require to be decomposed before application. The process of decomposing wastes is called composting and the decomposed material is called 'compost'. It is like well decomposed cattle manure, more powdery and lighter; in colour. Compost making involves keeping the dry organic waste materials in layers in pits and moistening either with water or with cow dung slurry. It takes about 8-10 weeks for complete decomposition.

iii. Green manures
Growing a crop purposely and incorporating it in the soil for manuring is called green manuring. Collecting green leave from all available sources and using it for manuring is green leaf manuring, Legumes alone are used as green manure crops usually. Ex. Dhaincha, Sesbania speciosa, S. rostrata, wild Indigo (Tephrosia purpurea), indigo (Indigofera tinctoria), Phaseolus trilobus, sunhemp, etc. iv. Concentrated organic manures
Concentrated organic manures are the organic manures which are rich in nutrients than bulky organic manures. Ex. guanos, fish manures, bone meal, oil cakes, etc. can be used in integrated nutrient management.

2.1.2 Legume planting
Including legumes in crop rotation is a very beneficial practice. Legumes are the plants which have nodules on their roots in which rhizobium ( a bacteria) lives. This bacteria have the ability to fix atmospheric nitrogen into the root nodules. They live in symbiosis with the plant Many other free living bacteria like Azotobacter, Beizerinckia, Clostridium, etc. and blue green algae like anabaena, nostoc etc. are also beneficial.

2.1.3. Bio-fertilizers
Bio-fertilizers are defined as biological preparations containing live or latent cells of efficient strains of nitrogen fixing or phosphorus mobilizing micro organisms. They are also known as microbial inoculants.

i. Rhizobium
In recent years bio-fertilizers have emerged as an important component of integrated plant nutrition system. The largest contribution of biological nitrogen fixation to agriculture is derived from the symbiosis between legumes and rhizobium species. Inoculation with efficient strains of rhizobium specific to each crop is essential for the nitrogen gains and better crop yields.
Nitrogen fixed by legume-rhizobium symbiosis is 100- 300 kg. nitrogen per hectare. ii. Blue green algae (BGA)
In Indian soils, the predominant genera are Anabaena, Nostoc, Calothrix') etc. BGA inoculation add up to 50 t/ha of organic matter and contributes 20-30 kg. nitrogen per hectare. iii. Azotobacter
Azotobacter is a free living bacteria which not only provides nitrogen but also produces a variety of growth promoting substances like indole acetic acid, gibberillins, B-vitamins and anti-fungal substances. Observations indicated that inoculation by Azotobacter was significant and it sprayed from 34-247 kg. N per hectare indifferent locations. iv. Azospirillum
Inoculation of Azospirillum has shown positive response in several field crops with an average response equivalent to 15.20 kg. nitrogen per hectare.

v. Myconhiza
Vesicular Arbuscular Mycorrhiza (VAM) are formed by non-septate fungi belonging to the genera Glomus, Gigaspora, Entrophospora, etc. it enhances the phosphorus availability and also the availability of other elements like potassium, sulphur and micronutrients like copper, zinc, aluminum, manganese, iron, etc. Mycorrhizal colonisation also allows introduced population of beneficial soil organisms like Azotobacter, Azospirillun and phosphate solubilizing bacteria to thrive. Reports show that VAM fungi can reduce fertilizer requirement by 25-30 per cent. vi. Phosphatic bio-fertilizers.
Phosphate solubilizing organisms such as Pseudomonas striata, Racillus polymixa, Asperigillus awamori, Pencillium digitatum etc. can grow with insoluble phosphate sources and convert them into soluble forms by a variety of mechanisms, Indian Agricultural Research Institute, New Delhi has prepared carrier based inoculant known as ''IRRI Microphos" culture using efficient strains of P. striata and B. polymixa.

2.2 ESSENTIAL NUTRIENTS
Plant growth is the result of a complex process whereby the plant synthesizes solar energy, carbon dioxide, water, and nutrients from the soil. In all, between 21 and 24 elements are necessary for plant growth. The primary nutrients for plant growth are nitrogen, phosphorus, and potassium (known collectively as NPK). When insufficient, these primary nutrients are most often responsible for limiting crop growth. Nitrogen, the most intensively used element, is available in virtually unlimited quantities in the atmosphere and is continually recycled among plants, soil, water, and air. However, it is often unavailable in the correct form for proper absorption and synthesis by the plant.
In addition to the primary nutrients, less intensively used secondary nutrients (sulfur, calcium, and magnesium) are necessary as well. A number of micronutrients such as chlorine, iron, manganese, zinc, copper, boron, and molybdenum also influence plant growth. These micronutrients are required in small amounts (ranging from a few grams to a few hundred grams per hectare) for the proper functioning of plant metabolism. The absolute or relative absence of any of these nutrients can hamper plant growth; alternatively, too high a concentration can be toxic to the plant or to humans.

2.3 SOIL CHARACTERISTICS
The capacity of soils to be productive depends on more than just plant nutrients. The physical, biological, and chemical characteristics of a soil—for example its organic matter content, acidity, texture, depth, and water-retention capacity—all influence fertility. Because these attributes differ among soils, soils differ in their quality. Some soils, because of their texture or depth, for example, are inherently productive because they can store and make available large amounts of water and nutrients to plants. Conversely, other soils have such poor nutrient and organic matter content that they are virtually infertile.
The way soils are managed can improve or degrade the natural quality of soils. Mismanagement has led to the degradation of millions of acres of land through erosion, compaction, salinization, acidification, and pollution by heavy metals. The process of reversing soil degradation is expensive and time consuming; some heavily degraded soils may not be recoverable. On the other hand, good management can limit physical losses. Good management includes use of cover crops and soil conservation measures; addition of organic matter to the soil; and judicious use of chemical fertilizers, pesticides, and farm machinery.
Organic matter content is important for the proper management of soil fertility. Organic matter in soil helps plants grow by improving water-holding capacity and drought-resistance. Moreover, organic matter permits better aeration, enhances the absorption and release of nutrients, and makes the soil less susceptible to leaching and erosion (Sekhon and Meelu 1994; Reijntjes, Haverkort, and Waters-Bayer 1992).

2.4 PLANT NEEDS
Plants need a given quantity and mix of nutrients to flourish. The higher the yield, the greater the nutrient requirement. A shortage of one or more nutrients can inhibit or stunt plant growth. But excess nutrients, especially those provided by inorganic fertilizers, can be wasteful, costly, and, in some instances, harmful to the environment.
Effective and efficient management of the soil storehouse by the farmer is thus essential for maintaining soil fertility and sustaining high yields. To achieve healthy growth and optimal yield levels, nutrients must be available not only in the correct quantity and proportion, but in a usable form and at the right time. For the farmer, an economic optimum may differ from a physical optimum, depending on the added cost of inputs and the value of benefits derived from any increased output.
CHAPTER THREE
3.0 NUTRIENT CYCLE
Soil nutrient availability changes over time. The continuous recycling of nutrients into and out of the soil is known as the nutrient cycle (NRC 1993).
The cycle involves complex biological and chemical interactions, some of which are not yet fully understood. A simplified version of this cycle of plant growth, based on Smaling (1993). The simplified cycle has two parts: “inputs” that add plant nutrients to the soil and “outputs” that export them from the soil largely in the form of agricultural products. Important input sources include inorganic fertilizers; organic fertilizers such as manure, plant residues, and cover crops; nitrogen generated by leguminous plants; and atmospheric nitrogen deposition. Nutrients are exported from the field through harvested crops and crop residues, as well as through leaching, atmospheric volatilization, and erosion.
The difference between the volume of inputs and outputs constitutes the nutrient balance.
Positive nutrient balances in the soils (occurring when nutrient additions to the soil are greater than the nutrients removed from the soil) could indicate that farming systems are inefficient and, in the extreme, that they may be polluting the environment.
Negative balances could well indicate that soils are being mined and that farming systems are unsustainable over the long term. In the latter instance, nutrients have to be replenished to maintain agricultural output and soil fertility into the future. The inexpensive supply of nutrients in the form of inorganic fertilizers was a key factor, along with improved modern seed varieties and adequate supplies of water, in the substantial increase in yields that exemplified the Green Revolution of the 1960s and 1970s.

3.1 NUTRIENT CONSERVATION AND UPTAKE
Nutrient conservation in the soil is another critical component of INM. Soil conservation technologies prevent the physical loss of soil and nutrients through leaching and erosion and fall into three general categories. First, practices such as terracing, alley cropping, and low-till farming alter the local physical environment of the field and thereby prevent soil and nutrients from being carried away. Second, mulch application, cover crops, intercropping, and biological nitrogen fixation act as physical barriers to wind and water erosion and help to improve soil characteristics and structure. Lastly, organic manures such as animal and green manures also aid soil conservation by improving soil structure and replenishing secondary nutrients and micronutrients (Kumwenda et al. 1996).
Improved application and targeting of inorganic and organic fertilizer not only conserves nutrients in the soil, but makes nutrient uptake more efficient. Most crops make inefficient use of nitrogen. Often less than 50 percent of applied nitrogen is found in the harvest crop. In a particular case in Niger, only 20 percent of applied nitro-gen remained in the harvest crop (Christianson and Vlek 1991). Volatilization of ammonia into the atmosphere can account for a large share of the lost nitrogen. In flooded rice, for example, volatilization can cause 20 to 80 percent of nitrogen to be lost from fertilizer sources (Freney 1996). These losses can be reduced, however. Deep placement of fertilizers in soil provides a physical barrier that traps ammonia. The use of inhibitors or urea coatings that slow the conversion of urea to ammonium can reduce the nutrient loss that occurs through leaching, runoff, and volatilization. With innovations of these kinds, better timing, and more concentrated fertilizers, nutrient uptake efficiency can be expected to improve by as much as 30 percent in the developed world and 20 percent in developing countries by the year 2020 (Bumb and Baanante 1996).

3.2 CONCLUSION
There are unending examples for integrated nutrient management which is difficult to mention all of them. Experiments are being conducted depending on the area, organic source availability in that area, crops and climatic conditions. They vary from place to place. It would be good if farmers realizes the need of organic matter to their soils and adopts this integrated nutrient management for sustaining the fertility of the soil.

REFERENCE Alston. J. M., P. G. Pardey, and V. H. Smith. 1998.
Financing agricultural R&D in rich countries:
What’s happening and why. Australian Journal of Agricultural and Resource42(1).
Ange, A. L. 1992. Integrated plant nutrition system on farm and soil fertility management: The major concepts. Rome: FAO. 1993. Integrated plant nutrition systems in European agriculture. Mimeo. Badiane, O., and C. L. Delgado, eds. 1995. A 2020 vision for food, agriculture, and the environment in Sub-Saharan Africa. Food, Agriculture, and the Environment Discussion Paper 4. Washington, DC: International Food Policy Research Institute.
Bationo, A., and A. U. Mokwunye. 1991. Alleviating soil fertility constraints to increased crop pro-duction in West Africa: The experience of the Sahel. In Alleviating soil fertility constraints to increased crop production in West Africa, ed. A. Uzo Mokwunye. Dordrecht: Kluwer Academic Publishers.
Benneh, George. 1997. Toward sustainable agriculture in Sub-Saharan Africa: Issues and strategies. IFPRI Lecture Series No. 4. Washington, DC: International Food Policy Research Institute.
Bockman, O. C., O. Kaarstad, O. H. Lie, and I.Richards. 1990.
Agriculture and fertilizers: Fertilizers in perspective. Oslo: Norsk Hydro.