Th e loss of major nutrients can be high in rice (Oryza sativa L.) fi elds, particularly rainfed rice, where water fl owing from fi eld to fi eld during periods of high rainfall not only reduces the nutrient use effi ciencies but also has the potential for environmental degradation. We examined the infl uence of deep point placement of N, P, and K briquettes compared to broadcast incorporation of N, P, and K on fl oodwater nutrient loads aft er fertilizer application and on the performance of wet season rice in a Vertisol. Broadcast application of N as urea resulted in an average 10 times higher amounts of ammonium N in fl oodwater compared to deep placement of urea briquette. Th e broadcast application of single superphosphate resulted in 67 times higher amounts of P in fl oodwater than plots receiving deep placed P. Th e fl oodwater NH 4 + -N and P content in the deep placement treatments were negligible-similar to fl oodwater N and P content without fertilizer application. Th e fl oodwater K amounts were also significantly lower with deep placed N-P-K briquettes. Signifi cantly higher grain and straw yields, total N, P, and K uptake, and N and P use effi ciencies were observed with deep placement of N-P-K compared to broadcast application of N-P-K. Deep placed N-P briquettes gave signifi cantly higher grain yield, straw biomass, total P and K uptake, apparent P recovery, and agronomic N and P use effi ciencies when plant spacing was reduced from 20 by 20 cm to 20 by 10 cm. Closer plant spacing led to better utilization of P and K and provided opportunities for deep placement of N-P or N-P-K briquettes in soils with low available P. Combining site specifi c characteristics (high soil pH, low percolation rate, high rainfall and surface runoff s) with plant spacing and N-P-K briquettes prepared based on site-specifi c nutrient requirements off ers potential for higher yields, improved fertilizer use effi ciency, balanced fertilization, and reduced nutrient losses.

Photobiomodulation (PBM) or low-level laser therapy (LLLT) in dentistry is an evolving science, with an increasing number of controlled clinical studies exploring its potential as a treatment modality. The present study provides an outline of the biologic mechanism of PBM and summarizes the findings of clinical studies of PBM for specific applications in oral medicine. Controversies and drawbacks associated with PBM, which require further research, are also identified. Current literature reports the potential of PBM in various applications in oral medicine. Furthermore, well-documented research confirms its efficacy in certain conditions, such as oral mucositis, recurrent herpes simplex infection, and burning mouth syndrome. The absence of any reported adverse effects is an advantage over conventional therapeutic modalities. While PBM has proved to be effective for some specific applications, it is not a panacea. The paucity in standardized studies, coupled with ambiguity over the laser parameters, has limited its credibility as a therapeutic modality.

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