Effect of nano urea on greenhouse gas emissions in transplanted rice (Oryza sativa L.) ecosystems

The application of conventional nitrogen fertilizer (urea) to improve rice crop yield has a significant influence on soil methane (CH4) and nitrous oxide (N2O) emissions. An experiment was conducted at Tamil Nadu Agricultural University, Coimbatore, wetlands farm, during the summer of 2023. A Randomized Block Design (RBD) was used with 8 treatments and 3 replications to evaluate the impact of different nitrogen application strategies on greenhouse gas emissions, specifically methane and nitrous oxide in transplanted rice, including the varying nitrogen levels. The study aimed to improve rice growth and yield through foliar application of nano urea, focusing on the rice variety CO55 with a recommended dose of NPK (150:50:50 NPK kg/ha). The results indicated that applying 75 kg nitrogen/ha (50 % of the recommended dose) as basal through conventional urea, along with 3 nano urea foliar sprays at 20, 40 and 60 days after transplanting (T5), resulted in significantly lower methane and nitrous oxide emissions compared with 100 % of the recommended nitrogen dose i.e. 150 kg nitrogen/ha applied through conventional urea, with 25 % used at basal, active tillering, panicle initiation and heading stage (T1) and 150 kg nitrogen/ha i.e. 100 % recommended dose of nitrogen applied through conventional urea, with 50 % as basal and 2 top dressings of 25 % of the recommended dose of nitrogen (RDN) each at active tillering and panicle initiation (T2)

Influence of Various Organic Sources on Soil Nutrient Status and Nutrient Uptake of Ragi under Guni Method

A field experiment was conducted during the kharif-2019 at the farmers field of Mylandahalli in Chikkaballapura distict of Karnataka, to study the effect of organic nutrient sources on soil nutrient status of finger millet under Guni method. The trial was framed out in randomized blocked design with twelve treatments replicated thrice. The results showed that supplement of SWC @ 50% N eq. + EBDLM @ 50% N eq. ha-1 + PG spray @ 3% (T9) had a significant effect on nutrient uptake, fertility status in soil and their values were statistically higher than all the other treatments. The findings of study reported that supplement of SWC @ 50% N eq. + EBDLM @ 50% N eq. ha-1 + PG spray @ 3% (T9) recorded significantly higher uptake of total nitrogen (124.7 kg ha-1), phosphorus (27.2 kg ha-1) and potassium (84.9 kg ha-1). Likewise, the same treatment had recorded superior in available soil nitrogen, phosphorus and potassium (413.8, 44.6 and 223.1 kg ha-1, respectively) compared to other treatments and recommended FYM (10 t)+100:50:50 kg N: P2O5: K2O ha-1 found to be least in soil nutrients and uptake during cropping period of kharif 2019

Performance of drip irrigation and fertigation levels on productivity and water requirement of aerobic rice (Oryza sativa L.) under rice-chia cropping system

Improving crop development and output requires efficient nutrient management, mainly when growing rice in an aerobic system using drip. Conventional rice farming and incorrect fertilizer delivery frequently result in a number of losses, including water loss, denitrification and volatilization. Split application of soluble fertilizers under drip irrigation techniques has become viable, increasing production while reducing water consumption. To address the problem, the trial was planned to find the optimum level of drip irrigation and fertigation for maximum productivity and water-use efficacy of aerobic rice. A study was conducted in the summer of 2022 and 2023 wetland farm Tamil Nadu Agricultural University, Coimbatore. The trial was operationalized using a randomized complete block design comprising 13 treatments, each duplicated thrice. Supplement of drip fertigation at the rate of 100% pan evaporation till 30 days after sowing (DAS), 150% pan evaporation till 60 DAS, 200% pan evaporation till 90 DAS with 125% recommended dose of fertilizer (25% as normal fertilizers + 75% as water-soluble fertilizers) exhibited notably greater number of productive tillers (416 and 434 m-2) and increased panicle weight (2.07 and 2.08 g) respectively in summer 2022 and 2023 as related to other treatments. The similar treatment demonstrated enhanced water-use efficacy (5.12 and 5.17 kg ha-mm-1), higher grain (4316 and 4446 kg/ha) and biological yield (9844 and 10221 kg/ha). Thus, it managed to conserve 25% and 24% of irrigation water compared to surface irrigation during both the years of the experimentations. Hence, adopting rice under the drip method in areas where water is scarce benefits the farmers