Suppose I have 1 ha land and want to have food crops, fodder, trees, farm pond, poultry, etc. Then how should I allocate land to these components? Is there any scientific methodology? Please share reference if any.
Check this links the articles maybe help you
Book Integrated Farming System
http://www.iifsr.res.in/sites/default/files/pdf/Bulletin%20%28Dr.%20J.P.%20Singh%29.pdf
http://www.hillagric.ac.in/edu/coa/agronomy/lect/agron-4711/Lecture%201%20Farming%20system%20scope%20importance%20and%20concept.pdf
https://library.wur.nl/ojs/index.php/Botswana_documents/article/view/16037/15510.
http://www.fao.org/docrep/w7365e/w7365e0c.htm
We know that on 0.4 ha area, one can keep three adult animals, likewise0.4 ha area can be kept for growing cereals, oilseeds and pulses, remaining 0.2 ha can be used for growing, vegetables, fruits etc. Infact, it is not an easy task, one has to learn every enterprise in depth , however, number of models have been developed by the scientists but its applicability varies from situation to sitution. For research papers, you can see journal of krishi vigyan available at www.iskv.in.
Professor Hartmut Vogtmann in his book: The Biological Garden. Okologischer Gartenbau (1990) shows calculations of land allocation for a person, or small family group. It has to do also with peoples' diet and what percentage of nutritional self sufficiency is sought. Check also Johnny Jeavon's Biointensive method of cultivation to increase plants density when land are is small.
I am not sure about your disciplinary background. Economists would address the question by applying some programming model e.g. linear programming, dynamic programming to optimize or maximize one or more objectives subject to available resources. Structure of the programme will differ depending on whether the objective is single e.g. maximize profit, or dual or multiple objective, e.g. maximize profit and family labour use and produce x amount of food grain.
If you are not an economist, should collaborate with an economist on such a problem.
Theoretically, it is done through Equimarginal Principle alternatively known as opportunity cost principle. Practically, the allocation problem can be tackled through Linear/non-linear Programming, depending upon the nature of the objective function. In this case, that is basically a maximization problem under constraints.
First, a site analysis should be done to study the topography, soil traits, availability of water, altitude, and more. This information is valuable to match your goal for land use and verify its feasibility. Only at this point the economics comes in the picture to substantiate or not the initial goal. Holistic Resource Management is the discipline mentioned here and its proponent is Allan Savory. Although Savory's work dealt primarily with range land management, I think its theoretical principles are applicable to small parcels of land. Permaculture design (Mollison and Holmgren) is also another valuable approach in support of integrated farming systems.