Nitrogen balance and use efficiency on dairy farms in Japan: a comparison among farms at different scales

Abstract

In recent decades, the rate of milk production per unit land area and per cow has increased with the intensification of the dairy system. The possible environmental risks arising from nutrients surpluses, such as nitrogen (N), are often evaluated using the N balance approach. In Hokkaido, the biggest dairy farming area in Japan, many dairy farms have started introducing a new dairy farming system called the total mixed ration (TMR) and biogas system. Feed and manure are managed at a community scale in these systems while each farm focuses primarily on milking cows. Thus, calculating the N balance for this system is complicated. Therefore, this study aimed to evaluate the N surplus and use efficiency (NUE), focusing mainly on the community-based dairy farming system, as described above. We investigated twenty dairy farms comprising a TMR centre (TMR-based farms) and nineteen conventional dairy farms (conventional farms). The Hokkaido dairy farms had a smaller N surplus and higher NUE than farms in other countries. The whole farm N surplus and NUE ranged from −163 to 701 kg N ha−1 and from 20% to 171% with median values of 40.5 kg N ha−1 and 69.5%, respectively. One of the possible reasons for the smaller N surplus and higher NUE is a lower stocking rate (averaged 1.3 cows ha−1) on Hokkaido dairy farms. There were strong relationships between feed N and N surplus because the studied dairy farms depended on purchased feed. In the comparison between the TMR centre and conventional dairy farms, the milk production level per cow and stocking rate tended to increase, and variations between farms decreased on the TMR-based farms. Increasing the amount of home-grown feed with pasture management is essential to decreasing N surplus for the new dairy farming systems.

Modelling of farm-gate nitrogen balance in dairy farming - case study of Latvia

“…Moreover, ensuring sustainable farm-gate N balance could be the most realistic option, especially for intensive dairy farms [7]. The evaluation of N balance on farm level, where total N inputs and outputs are estimated and the difference (N surplus) and ratio (N use efficiency) are quantified, is caried out worldwide to evaluate N use outcomes of an agricultural system and the risk of N losses in environment [8]. From the practical point of view, the N balance and NUE in different dairy systems, for example, depending on grazing intensity [4; 9] or farming scale [8] have been analysed.…”

“…The evaluation of N balance on farm level, where total N inputs and outputs are estimated and the difference (N surplus) and ratio (N use efficiency) are quantified, is caried out worldwide to evaluate N use outcomes of an agricultural system and the risk of N losses in environment [8]. From the practical point of view, the N balance and NUE in different dairy systems, for example, depending on grazing intensity [4; 9] or farming scale [8] have been analysed. The latest studies have become more complex: De Klein et al (2017), involving the case studies of several European countries, the USA and Oceania, outline the problematics on the assumptions used in the calculations of NUE and N surplus and the use of these indicators in setting realistic environmental policy goals [10], on the other hand, Hutchings et al (2020) estimate the existing level of NUE of European agricultural production and model possibilities to increase it by technical measures [11].…”

Green Total Factor Productivity of Dairy Farming in China: Based on the Perspective of Scale Heterogeneity

“…There are different sizes of dairy cattle farming, depending on the number of cows farmed, the farming scale can be divided into small, medium, and large scale (Mosheim and Lovell, 2009;Toda et al, 2020). Different farming scales using different environmental treatments will have different pollutant dissipation indices (Schiano et al, 2017;Adenuga et al, 2019).…”

Focus on reactive nitrogen and the UN sustainable development goals

“…NUE is also a decisive indicator in animal husbandry. Toda et al (2020) estimated N balances and compared the NUE of dairy farms in Japan using either a total mixed ration (TMR) and biogas system or conventional feeding. They found a considerable variability in N surplus and NUE and identified the stocking rate and feed N as the main influencing factors.…”