In energy calculation, the two following indicators are used: energy efficiency (E) and production energy requirements (e). Both of the above indicators have limited implementation for evaluating food products because they disregard nutrients and sensoric features. For this reason indicators in scientific papers representing energy input for cereal unit production, digestive protein, plant oils, sugar and other reserve materials are calculated [ LEWIS 1982, NOWACKI 1988]. According to many authors, energy indicator is a very good criterion for evaluating fodder crop rotation [SZWEJKOWSKI 1999, STUPNICKA-RODZYNKIEWICZ and LEPIARCZYK 1991].
Economists, aware of these difficulties, paid a lot of attention to methodological research into setting proper equivalents for material and agro-technological input evaluation [KIJOWSKA 1986, ANUSZEWSKI 1987, PAWLAK 1988, WIELICKI 1990a, MICHALASKI 1991, SOBCZAK 1982, SOBCZAK et al. 1990].
In the majority of Polish scientific works the evaluation energy input for agro- technology is given along with fuel, human and animal labour , tractors and agriculture transportation inputs. This method enables the simplification of analysis, input balancing, and the calculation of production effectiveness, represented by various indicators [WÓJCICKI 1981, ANUSZEWSKI 1997, SOBCZAK 1982].
In Czech scientific works, KREJČĺŘ (1986), STRAŠIL and ŠIMON (1991) and others evaluated plant production energy. Additionally, fuel, with after harvest left-overs and light energy used by plants during vegetation periods, is included. The rest of the "added" energy is composed of materials, human and mechanical labour. In Polish and foreign scientific works, a lot of attention was devoted to studies on the possibilities of the reducing energy input for soil cultivation and plant protection.
MATTHEUS (1982) compared simplified systems in soil cultivation beginning from traditional plough calculation to plough-less calculation and direct sowing. He proved that the direct sowing of winter wheat decreased the energy input by five times. Less energy is used while using equipment such as harrows and listers than when using ploughs [DZIENIA and SOSNOWSKI 1990]. It was also shown that the abandoning of plant cultivation after harvest in the plough system for winter cereals about 14 to 40%, the usage of a soil miller and flat ploughing by about 20 to 47%, and direct sowing by about 49 to 77%.
In the cultivation of winter triticale after summer barely on light soil, listers and string rollers may be used instead of ploughing [ DZIENIA et al. 1994]. The reaction of triticale to direct sowing is negative owing to the pressure of perennial weeds. In the multi-directional research of GONETA and ZAORSKI (1988) fuel consumption, which depends on the depth of ploughing in different humidity and soil compactness, speed of ploughing and tractor power, was analyzed. The authors showed that in the basic system of soil cultivation fuel consumption savings from 40 to 50 % were possible. This kind of research was developed by CZYŻ et al. (1995). According to them, soil cultivation for growing winter barley may be modified by different methods in order to save fuel. It was also shown that deep ploughing in the fall and the usage of tractors with twin tires along with fluffing the tire-tracks has a positive influence on the crop and the mass of the summer root barley system.
In plant protection, the use of a new generation of pesticides in small volumes saves energy enabling a 6 or 7-fold decrease in the amount of liquid used per hectare [LEWIS 1982]. Further possibilities of energy savings may be obtained by the usage of lighter, precision sprays, which protect the soil from packing. The usage of various simplifications in plant agro-technology requires more training of farmers. Researchers agree that these and other practices, which allow energy saving in cultivation-protecting operations will have a chance to be implemented by the farmers. [FLUCK 1981, NAWROCKI 1984, ŠIMON 1990, NOWICKI and SZWEJKOWSKI 1992, DZIENIA et al. 1994].