Grain, milling, and head rice yields as affected by nitrogen rate and bio-fertilizer application

Abstract

To evaluate the effects of nitrogen rate and bio-fertilizer application on grain, milling, and head rice yields, a field experiment was conducted at Rice Research Station of Tonekabon, Iran, in 2013. The experimental design was a factorial treatment arrangement in a randomized complete block with three replicates. Factors were three N rates (0, 75, and 150 kg ha-1) and two bio-fertilizer applications (inoculation and uninoculation with Nitroxin, a liquid bio-fertilizer containing Azospirillum spp. and Azotobacter spp. bacteria). Analysis of variance showed that rice grain yield, panicle number per m2, grain number per panicle, flag leaves area, biological yield, grains N concentration and uptake, grain protein concentration, and head rice yield were significantly affected by N rate, while bio-fertilizer application had significant effect on rice grain yield, grain number per panicle, flag leaves area, biological yield, harvest index, grains N concentration and uptake, and grain protein concentration. Results showed that regardless of bio-fertilizer application, rice grain and biological yields were significantly increased as N application rate increased from 0 to 75 kg ha-1, but did not significantly increase at the higher N rate (150 kg ha-1). Grain yield was significantly increased following bio-fertilizer application when averaged across N rates. Grains N concentration and uptake were significantly increased as N rate increased up to 75 kg ha-1, but further increases in N rate had no significant effect on these traits. Bio-fertilizer application increased significantly grains N concentration and uptake, when averaged across N rates. Regardless of bio-fertilizer application, head rice yield was significantly increased from 56 % to 60 % when N rate increased from 0 to 150 kg ha-1. Therefore, this experiment illustrated that rice grain and head yields increased with increasing N rate, while bio-fertilizer application increased only rice grain yield.

Estimation of Genetic Parameters for Six Genotypes of Rice Crop Under the Effect of Different Combinations of Fertilizers

“…Or the reason for the increase in leaf area may be due to the role of nitrogen fertilizer, which helps in the growth of leaf expansion, especially its width and area. This result is consistent with what was found by [17,18]. The results of Table (3) showed a significant difference between the rice varieties, where the variety Mishkhab2 achieved the highest average of 24.59 cm 2 , while the Anber33 variety achieved the lowest average of 18.82 cm 2 .…”

Do cover crops improve the productivity and industrial quality of upland rice?

“…Nitrogen is the second most extracted nutrient, the most removed by rice (Crusciol, Fernandes, Carmeis Filho, & Alvarez, 2016a), and limits the growth and productivity of cereals (Zhou et al, 2017). Greater N availability results in increased milling yield (Reis et al, 2018) and head yield (Firouzi, 2015;Reis et al, 2018) of rice; therefore, it improves the industrial quality and can influence the price of rice (Laenoi, Rerkasem, Lordkaew, & Promuthai, 2018). Thus, cover crops that accumulate and increase the availability of nutrients, especially N, may favor the development, productivity, and postharvest quality of rice cultivated in succession.…”

Nutritional qualities and heavy metals accumulation in grains: A study on lowland irrigated rice with different fertilizer inputs and growing seasons

“…Hence, the almost 1% protein gain could be a result of high N inputs. The recommended N input can be the theoretical upper limit of N inputs to show a positive impact on net protein (Firouzi, 2015). The dry seasons of 2020 resulted in a significantly higher protein content compared to other seasons Figure 5.…”