Nutrient Accumulation and Partitioning of Current Rice Cultivars Under Direct-Seeding, Delayed-Flood Irrigated System

Date of Graduation

12-2025

Document Type

Thesis

Degree Name

Master of Science in Crop, Soil & Environmental Sciences (MS)

Degree Level

Graduate

Department

Crop, Soil & Environmental Sciences

Advisor/Mentor

Roberts, Trenton

Committee Member

Nicolli, Camila

Second Committee Member

Drescher, Gerson

Third Committee Member

Hardke, Jarrod

Keywords

Nutrient Management; Nutrient Partitioning; Nutrient Uptake; Rice; Rice Cultivars; Soil Fertility

Abstract

Adequate fertilizer recommendations are essential for profitable, high-yielding rice and keeping pace with a growing population's food needs. The objective of this study was to investigate dry matter accumulation, nutrient accumulation, and partitioning of four current rice cultivars in delayed-flooded irrigation systems under two fertilization regimes. The research was established in 2022 and 2023 at the Rohwer Research Station (RRS) and the Pine Tree Research Station (PTRS). A factorial treatment arrangement was used, including two fertilizer rate treatments of 100 and 125% of current soil-test recommendations for nitrogen (N), phosphorus (P), and potassium (K), and four cultivars (CLL 16, Diamond, RT 7521 FP, and Titan). Aboveground plant biomass was sampled at seven developmental times: V3, V5/6, 2WPF, 4WPF, 6WPF (only 2023 season), 50% heading, and maturity. At 50% heading and maturity, samples were partitioned into stems, leaves, and spikelets or grains. Samples were submitted for nutrient concentration analysis by ICP. Differences in yield (P ≤ 0.05) were observed due to the cultivar effect. RT 7521 FP had the largest yield (10,883 kg ha-1), while CLL 16 (9,863 kg ha-1), Diamond (9,445 kg ha-1), were statistically equal but greater than Titan (7,885 kg ha-1) which had the lowest yield. For total dry matter accumulation, Titan had the lowest biomass production (18,824 kg ha-1), while CLL 16 (22,561 kg ha-1), Diamond (21,609 kg ha-1), and RT 7521 FP (23,237 kg ha-1) were statistically equal for biomass production. Similar trends occurred for total nutrient accumulation, in which the cultivars with higher biomass tended to accumulate the most macro and micronutrients. This work provides a greater understanding of all essential nutrient uptake timing and demand for the newest rice cultivars, providing new information for fine-tuning fertilizer recommendations.

This document is currently not available here.

Share

COinS