Iron (Fe) deficiency in humans caused by inadequate dietary intake is a global nutritional problem. The field experiments in this paper were conducted in the same paddy field over two consecutive years during the dry seasons of 2017 and 2018. The aims of the experiments were to evaluate the effects of iron application methods (soil or foliar alone and a combination of soil + foliar) on the Fe content in brown rice grain and to compare the grain yields of three rice cultivars, namely Chinat1 (poor Fe grain concentration), Riceberry and Tubtim Chumpae (rich Fe grain concentration). The results show that all iron application methods significantly increase the iron content of brown rice grains in comparison with non-iron application in two cropping years. The iron application to the soil combined with foliar gave the highest iron content in the brown rice grain. However, the responses to the iron application methods were different among rice cultivars. The highest grain iron contents of Chainat1 and Riceberry were shown in the combination of soil and foliar application, whereas Tubtim Chumpae had the highest grain iron content in the foliar application alone. The differences in grain yield were affected by the rice cultivar, but not by iron application methods. The Chainat1 produced the highest grain yield. In addition, Chainat1 had the strongest correlation between brown rice grain iron content and grain yield for both cropping years.

Rice ratooning is a widely adopted practice in southwest Louisiana because it allows production of an additional crop from the existing rice stand with relatively low input requirements. Although ratoon-crop yield is generally lower than main crop yield, the additional harvest can improve overall system productivity and profitability due to reduced establishment and production costs. This study evaluated the effect of seeding rates on ratoon yield using data collected from 2016 to 2021 across nine seeding rates ranging from 13.0 to 104.3 kg ha⁻¹, 18 rice varieties, and 37 trials. Linear mixed-effects models were used with seeding rate and plant density as fixed effects and year and variety as random effects. Ratoon yield increased significantly with seeding rate (R = 0.285, p < 0.001), with an estimated gain of 7.48 kg ha⁻¹ for each 1 kg ha⁻¹ increase in seeding rate. The estimated optimum seeding rate was 72 kg ha⁻¹; however, ratoon yield responses remained relatively broad near the optimum. Therefore, a practical seeding rate range of 50–80 kg ha⁻¹ is recommended to maximize ratoon yield while accounting for environmental and varietal variability. Main crop yield was not correlated with ratoon yield (R = −0.044). Variance component analysis showed that year and variety contributed substantially to overall yield variability. These results indicate that ratoon yield is significantly influenced by seeding rates, with moderate to high seeding rates supporting greater ratoon productivity, while environmental and genetic factors also play important roles.