Synergy and Transition of Recovery Efficiency of Nitrogen Fertilizer in Various Rice Genotypes under Organic Farming

Abstract

Despite the growing demand for organic products, research on organic farming (OF) such as genotype screening, fertilizer application and nutrition uptake remains limited. This study focused on comparisons of the apparent recovery efficiency of nitrogen fertilizer (REN) in rice grown under OF and conventional farming (CF). Thirty-two representative conventional Japonica rice varieties were field grown under five different treatments: control check (CK); organic farming with low, medium and high levels of organic fertilizer (LO, MO and HO, respectively); and CF. Comparisons of REN between OF and CF classified the 32 genotypes into four types: high REN under both OF and CF (type-A); high REN under OF and low REN under CF (type-B); low REN under OF and high REN under CF (type-C); and low REN under both OF and CF (type-D). Though the yield and REN of all the rice varieties were higher with CF than with OF, organic N efficient type-A and B were able to maintain relatively high grain yield under OF. Physiological activities in flag leaves of the four types from booting to maturity were subsequently investigated under OF and CF. Under OF, high values of soil and plant analyzer development (SPAD) and N were observed in type-B varieties, while in contrast, both indexes slowly decreased in type-C varieties under CF. Moreover, the decline in N content in type-C and D varieties was greater under OF than CF. The decrease in glutamine synthetase (GS), glutamic-pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) activity in flag leaves was smaller under OF than CF in type-A and B varieties, while in contrast, type-C and D varieties showed an opposite trend. The findings suggest that OF slows the decline in key enzymes of N metabolism in organic N-efficient type rice, thus maintaining a relatively high capacity for N uptake and utilization and increasing yield during the late growth period. Accordingly, we were able to screen for varieties of rice with synergistically high REN and high grain yield under OF.

Estimating Nitrogen and Chlorophyll Status of Romaine Lettuce Using SPAD and at LEAF Readings

“…It has been reported that the Chl and N concentrations determined in the laboratory have high correlations with the SPAD readings for a variety of plant species, including: corn (Hurtado et al, 2010), tomato (Ferreira et al, 2006), cabbage (Westerveld et al, 2003), rice (Huang et al, 2016) and mangrove (Dou et al, 2018). High correlations have also been reported with atLEAF meter in corn, wheat (Zhu et al, 2012) and sage (Dunn et al, 2018a).…”

Quantity and monetary value of agrochemical pollution from intensive farming in Indonesia

“…A study suggests that organic farming practice slows the decline in key enzymes of nitrogen metabolism in organic nitrogen-efficient type rice, thus maintaining a relatively high capacity for nitrogen uptake and utilization and increasing yield during the late growth period. Cultivating selected cultivars varieties of rice with the synergistically high efficiency of nitrogenous fertilizer and high grain yield under organic farming is able to increase the efficiency (Huang et al , 2016).…”

Economic indicators of profitability in the production of organic and conventional food and psychological ways of overcoming the crisis in managers due to the possible decline of business during the COVID-19 pandemic

“…When comparing organic and conventional food, the first thing that it must have been borne in mind the fact that the market for organic food and its production is constantly growing (IFOAM, 2020). Higher demand for organic products, as well as, political support is affecting the growth of the organic food market (Huang et. al., 2016).…”