User-friendly Greehouse Gas calculators to assess water-saving practices
in rice fields in Arkansas
Abstract
Globally, the scarcity of water makes it necessary to look for
alternative practices to increase sustainability in agricultural
systems. In the US, Arkansas is the largest rice producer with a great
water demand, which contributes to the decline of the state’s
groundwater resources. Different practices are proposed to decrease the
on-farm water use, and hence decrease both greenhouse gas (GHG)
emissions associated with flooded periods and the use of energy to pump
water. In this work, five water-saving practices are evaluated:
Alternate Wetting and Drying, Row Cropping, Land Levelling, Multiple
Inlet Rice Irrigation with Polypipe, and the use of new hybrids. Over
the last years, due to the climate change concern, a number of GHG
calculators have been developed to assess agricultural practices. These
tools are designed to have a user-friendly interface, and they are based
on IPCC emission factors and both process-based and empirical models.
Cool Farm Tool, that provides an estimate of CO2eq emissions per unit of
area or grain yield, was identified in one study as the highest-rated
tool available in the public domain for single crop assessment.
Fieldprint calculator provides a more extensive data output, reporting
the impact of agronomic practices in five resource areas, including GHG
and irrigation water use. The comparison of one farm’s impact against
the state and country average are additionally provided. Comet-Farm,
another of these tools, can compare actual farm practices with
alternative future scenarios. Therefore, one of the challenges when
using these tools is the comparison between them, mainly due to
differences in scope, calculation methods, and reporting units. In the
present work, we aim to assess water and GHG emissions saving potential
of the five experimented water¬¬-saving practices by outputs of the
three user-friendly calculators. The ease of use, similarities, and
differences between these tools will be evaluated. Ten rice fields with
different water-saving techniques are under our observation in Eastern
Arkansas. Data collected from sensors installed in the fields and
inquiries from farmers will be used as inputs for these tools. This work
aims to advise farmers on the implementation of these practices with the
final aim to encourage statewide adaptation of water-saving incentive
strategies.