2024 NERREC Field Day

Arkansas Rice Advanced Variety Trials and Arkansas Rice Production Trials

– Dr. Jarrod Hardke (UADA)

Long-Term Row Rice and Soybean Rotation with Cover Crops

– Dr. Steve Green (ASU) and Dr. Trent Roberts (UADA)

Integrated rice management for reduced water and yield-scaled GHG emissions

– Dr. Arlene Adviento-Borbe and Dr. Joseph Massey, USDA-ARS Delta Water Management Research Unit

The climate crisis is as certain, and it has begun. And it is well on its way to becoming more expensive and effects will be profound on rice production. Climate-smart rice farming directly links crop production to reduction of irrigation water use and greenhouse gas emissions from paddy rice fields. This approach consists of integrated crop and water management to reduce irrigation and methane and nitrous oxide gas emissions while sustaining high grain yields. Several management practices such as timing of irrigation schedules, using the right rate and type of N fertilizers, and choosing hybrid cultivars have the potential to reduce GHG emissions and water use without yield penalty.

A recent field study in NE Arkansas demonstrated that the practice of furrow rice irrigation decreased irrigation water use by 35% relative to conventional continuously flooded rice irrigation. Also, field screening of hybrid cultivars indicated that some Ricetec’s hybrid cultivars (RT7521, RT7421) have the potential to decrease CH₄ emissions by 15-20% compared to inbred cultivars. While the use of urea enriched with sulfate fertilizer showed minimal N₂O emissions in continuously flooded rice fields. The combined impacts of furrow rice irrigation and low emitting CH₄ hybrid cultivars decreased global warming potentials of CH₄ and N₂O emissions by about 55% with highest grain yield. With more evidence supporting a decrease in irrigation water use and GHG emissions among high yielding cultivars, opportunities to explore integrated crop management practices may aid in the development of effective climate-smart farming in rice agroecosystems.

Simple automation to improve farmer quality of life and irrigation efficiency

Exciting developments are occurring in technologies and practices that promise to save producers time, money, and irrigation water. For example, advances in remote irrigation pump control are making it possible for farmers and their staff to remotely shut off irrigation pumps, allowing irrigation to be stopped in a timely manner. A recent case study of a NE Arkansas farm determined that a total of 780 pump operations for the 43 wells servicing 2,800 acres of irrigated rice, soybean, and corn occurred in 2021.  Of these 780 operations, 382 were to completely shut off the irrigation pumps and 398 were to switch the well from one field to another.  Given the distribution of wells and fields of this particular operation, the total miles driven to completely shut off the wells was estimated to be about 1900 miles. Moreover, about one-half of these shutoff activities occurred at night when no one was present to perform pump shutoff, leading to about 10% excess pumping for the 2021 season. Remote pump control allows the farmers and staff to turn off the wells using a phone application. Quality of life (QOL) benefits of remote pump shutoff are difficult to determine and will vary from producer to producer and farm to farm but are expected to factor heavily when calculating return-on-investment and payback periods of remote pump control technologies.

Another simple use of technology specific to rice production is early cascade irrigation shutoff (ECIS). Cascade flooding is the conventional method of irrigating rice practiced on about 50% of Arkansas rice acres. In ECIS, a water depth sensor is used to notify the producer when an upper rice paddy is full of water, allowing the irrigation pump to be shut off in a timely manner (figure below). This approach conserves irrigation water by reducing field runoff, resulting in water savings on par with multiple-inlet rice irrigation that features the use of plastic tubing that some producers prefer not to use. Farm tests of ECIS to date are consistent with modeling results and grain yields have not been impacted.

Cascade rice flood irrigation showing early cascade irrigation shut off (ECIS)

Real-Time Measurement of GHG in Field-Scale Row Rice Productions Systems

– Dr. Michele Reba, USDA-ARS Delta Water Management Research Unit

Rice Disease Research

– Dr. Camilla Nicolli (UADA)

The Rice Pathology Team contributes to the Rice Crop Care program at the Rice Research & Extension Center. This comprehensive Plant Pathology research and extension program is dedicated to advancing agricultural practices not only for rice but also for soybean and corn crops. The Team is involved in several significant projects funded by the Arkansas Rice Research and Promotion Board. Activities include monitoring fungicide resistance in rice sheath blight to enhance management strategies and reduce yield losses, integrating host resistance with fungicides to control Cercospora in rice, and assessing the prevalence and stability of host resistance to rice blast races in Arkansas. Additionally, the team provides crucial support to the Rice Breeding Program by screening rice diseases across various rice varieties and ensuring the development of robust and disease-resistant strains. The Team also conducts trials to evaluate various disease management strategies, which include assessing the effectiveness of fungicides and bio-products. Our efforts help identify promising disease management strategies for combating sheath blight, blast, Cercopora and false smut in rice, and addressing substantial challenges faced by regional growers. Furthermore, we collaborate with industry partners to conduct trials for testing essential fungicides to controlling diseases like sheath blight in rice. Through these trials, the Plant Pathology program plays a vital role in identifying and recommending the most suitable fungicides to combat emerging and existing fungal diseases, safeguarding crop yields, and ensuring food security. Website: https://ricecropcare.uada.edu

Weed Management in Rice and Soybean

– Dr. Bob Scott (UADA)