Grain Yield Response of Twelve New Rice Cultivars to Nitrogen Fertilization.

The purpose of the cultivar by nitrogen (N) studies is the observation and analysis of the response of new rice (Oryza sativa L.) cultivars to N fertilization in order to determine the optimal N fertilizer rates across an array of soils and environments in which rice is grown in Arkansas. Twelve cultivars were studied in 2021 and included: ARoma17, CLL16, CLL17, CLM04, DG263L, DGL274, Diamond, Jewel, Lynx, ProGold1, ProGold2, and PVL03 at 3 University of Arkansas System Division of Agriculture locations: the Northeast Research and Extension Center (NEREC), the Pine Tree Research Station (PTRS), and the Rice Research and Extension Center (RREC). Seed treatment and seeding rates followed current recommendations and production practices. The grain yields were fair to good for most cultivars studied at the 3 locations in 2021, with lodging ranging from mild to none, with a few plots severely damaged at the PTRS location. The 2021 season was the first year the cultivars DGL274 and PVL03 were included, and the second year for DGL263L, ProGold1, and ProGold2; therefore, there is insufficient data to make an N rate recommendation at this time, and hence the response to N reported here can serve as a guide while more data is collected in subsequent years. Multiple years of results for ARoma17, Diamond, CLL16, CLM04, Jewel, and Lynx provide evidence that these cultivars should have good yields with minimal to no lodging if 150 pounds (lb) of N/ac is applied in a two-way split of 105 lb N/ac at the preflood timing followed by 45 lb N/ac at midseason when grown on silt loam soils and 180 lb N/ac in a two-way split of 135 lb N/ac at the preflood timing followed by 45 lb N/ac applied at midseason when grown on clay soils. [ABSTRACT FROM AUTHOR]