Estimation of short- and long-term floor and ceiling prices for manure in a crop and livestock farms exchange

Abstract

Organic matter is a key element of soil fertility. However, in-soil stocks of organic matter are in decline in specialized crop farms. Reintroducing organic fertilizers could be a way to increase or at least maintain organic matter stocks in these soils. Straw/manure exchanges between crop farms and livestock farms could improve overall land fertility and thus the long-term income of farmers. Here we used a bioeconomic model to estimate the agronomic and economic benefits of straw/manure exchanges as part of a strategy to improve soil fertility. Iterative simulations were run with prices of farmyard manure varying from €0 to €20 ton−1 to identify the price at which a crop farm can buy manure and sell straw without degrading its net income (manure ceiling price) compared to purchasing mineral fertilizer only and ploughing back straw. Parallel simulations were run to identify the price at which a livestock farmer can sell manure and buy straw without degrading its net income (manure floor price) compared to keeping all manure on the farm and buying straw on the market. The key new contributions of this study are that it (i) considers the characteristics of manure beyond its short-term fertilizing value, i.e., better mineralization of humus and a 10% increase in crop yields, (ii) estimates both the economic and agronomic benefits of manure and (iii) assesses the impacts of uncertainties on manure effects and prices. The results show that it is profitable for a French farmer in a conventional field crop system to buy manure at a price between €10 ton−1 in the short term and €18 ton−1 in the long term. The results also show that it is still economically advantageous for a livestock farmer to sell part of their manure, even at a very low price. This study shows that it is possible to better distribute manure resources over a territory in a way that enriches the soils of crop farms without degrading the soils of livestock farms.

Assessment of Beef Manure Economic Value by the Method of Equivalent Green and Mineral Fertilizer Substitution

“…The authors emphasized that, under free agreement conditions, this price often reached a value of 9.28 USD/t. Investigating short-and long-term floor and ceiling prices for manure in a crop and livestock farm exchange, Thiery et al [33] simulated farmyard manure prices varying from 0 to 21.76 USD/t to identify the manure ceiling price compared to purchasing mineral fertilizer only and plowing back straw. Their iteration led to the conclusion that for French farmers in a conventional field crop system, an acceptable manure price should be between 10.88 USD/t in the short term and 19.59 USD/t in the long term.…”

“…), and as awareness grows about its significant utility value [22], there is an increasing need to define its value, i.e., its price [32]. According to Thiery et al [33], even in a developed country such as France, manure has no fixed 'commodity' market price but only locally defined pricing recommendations. Their research, published in April 2023, was the first attempt to estimate the economic value of manure.…”

Can Soil Improvers (Biochar, Compost, Insect Frass, Lime, and Zeolite) Achieve Phytostabilization of Potentially Toxic Elements in Heavily Contaminated Soil with the Use of Purslane (Portulaca oleracea)?

“…Compost differs from biochar, among other characteristics, in the fact that added C is much less long-lived in soil, as microbial decomposition results in an expected mineralization rate of ca. 10% within the first two years of application [18]. Thus, apart from being used as a means of PTE retention with similar mechanisms as those of biochar, compost improves soil physico-chemical properties and the availability of nutrients to plants, thus boosting their vigor [19,20].…”