Naslov
Modeling the cost-effectiveness of direct replacement of mineral forms of N, P and K with organic fertilizers

Autori
Lončarić, Zdenko ; Jelić Milković, Sanja ; Ravnjak, Boris ; Nikolin, Iva ; Perić, Katarina ; Nemet, Franjo ; Ragályi, Péter ; Szécsy, Orsolya ; Rékási, Márk ; Lončarić, Ružica

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
58th Croatian & 18th International Symposium on Agriculture / Carović-Stanko, Klaudija ; Širić, Ivan - Zagreb : Agronomski fakultet Sveučilišta u Zagrebu, 2023, 7-7

Skup
58th Croatian & 18th International Symposium on Agriculture

Mjesto i datum
Dubrovnik, Hrvatska, 11.02.2023. - 17.02.2023

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
manures ; transport costs ; manure application ; nutrient content ; inflection point

Sažetak
The cultivation of field crops in recent decades has been marked by the negative impacts of climate change, increased risk of soil degradation and the risk of environmental stress, and the latest challenge is the increase in the price of energy sources and mineral fertilizers. At the same time, in the Republic of Croatia there is a large proportion of arable soils with low SOM content, like in the soils analyzed in 2020, almost half of the soil was found to have less than 2% SOM with an average content of <1.6%. On the other hand, the development of sustainable agriculture and digital technologies enables not only the precise application of fertilizers, but also the precise modeling and calculation of the optimal fertilization and the profitability of fertilization including mineral and/or organic fertilizer. Therefore, we developed a model to help make decisions in fertilization based on the cost-effectiveness of replacement of mineral fertilizers (containing N, P and K) with organic fertilizers. The model does not consider the cumulative fertilizing and improving effect of organic fertilizers on soil fertility, but only the direct value of N, P and K in the organic fertilizer. The model is based on data on organic fertilizer (N, P, K content and dynamics of N availability), data on soil fertility and crop needs (for calculating optimal amounts of N, P and K in fertilization), data on plot distance and available mechanization (for calculating the costs of transport and application of organic fertilizer) and the prices of mineral and organic fertilizers (for total costs of mineral and organo-mineral fertilization). The result of the model is the calculation of the total costs of fertilizing only with mineral fertilizers and with a combination of mineral and organic fertilizers, and an analysis of the cost structure (fertilizer purchase cost, transport cost, and fertilizer application cost) depending on the price of the fertilizer (mineral and organic), nutrient content (N, P and K), distance and the size of the arable plot, the method of transport, the capacity of the spreader, the cost of the employee’s work, etc. The model allows comparison of profitability by simply changing the value of one, several or all input variables. The result contains information on the share of transport and application costs in total fertilization costs, for example a share of 23.7% if 0.2% N in fertilizer and plot distance of 0.5 km and a share of 8.5% if 0.8% N in fertilizer. Also, the models calculate the inflection points when organo-mineral fertilization becomes cheaper than mineral fertilization. The inflection point can be expressed as minimum nutrient content in manure (N, P and/or K), as maximum plot distance, minimum spreader capacity or as a combination of different values. For example, in fertilizing corn on medium-fertile soils inflection point is when organic fertilizer contains 0.5% N, and in fertilizing wheat it should be at least 0.64% N with the appropriate proportional content of P and K.

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija), Biotehnologija

POVEZANOST RADA