Transplanting single seedlings rather than seedlings in clumps has been increasingly attractive in hybrid rice production in China due to reduced seed requirements and higher grain yield. This study was conducted to determine grain yield and nitrogen (N) utilization in response to reductions in the N rate in hybrid rice under single-seedling transplanting. Field experiments were done in 2015 and 2016 on a moderate to high fertility soil at the Experimental Farm of Hunan Agricultural University, China. The hybrid rice cultivar Liangyoupeijiu (LYPJ) was used in 2015, and two hybrid cultivars LYPJ and Xiangliangyou 900 were used the next year. In each year, the rice plants transplanted with a single seedling per hill were grown with three N rates, including the usual N rate (150 kg ha–1) and two reduced N rates (120 and 90 kg ha–1). Grain yield, yield attributes, and N uptake and use efficiency were determined for each N rate. Significant reduction in grain yield was observed in only one of three cultivar-year combinations when N rate was reduced by 20% (from 150 to 120 kg ha–1), and the magnitude of yield reduction was only 4%. Although significant reduction in grain yield was observed in two of the three cultivar-year combinations when N rate reduced by 40% (to 90 kg ha–1), the highest yield reduction was only 7%. Yield attributes were generally changed slightly when N rate was reduced by 20%, while compensation among yield attributes and N utilization characteristics could explain why a 40% reduction in N rate did not result in substantial yield loss. Partial factor productivity of applied N (PFPN) was increased by 21–24% and 56–63% with 20% and 40% reductions in the N rate, respectively. The higher PFPN with a reduced N rate was attributed to higher recovery efficiency of applied N (REN) or to both higher REN and internal N use efficiency. Our study suggests that reducing N rate does not necessarily result in yield loss due to compensation among yield components and increased N use efficiency in hybrid rice transplanted as single seedlings under moderate to high soil fertility conditions.

Words should be chosen and used carefully so that they convey the meaning or meanings that you intend—and do not convey any unintended or double meanings. Writing should leave little ambiguity or uncertainty about what you are referring to—unless some purposeful ambiguity is desired. Sometimes words that are abstract or superficial may be chosen to suit the writer's purpose. For example, there is a long tradition of euphemistic writing. But such use of words should be well-considered and deliberate, not the result of carelessness or indifference.

An evaluation was conducted in eastern India over three years, 2005–2007, to compare the performance of certain System of Rice Intensification (SRI) practices: transplanting single, young (10-day-old) seedlings in a square pattern; no continuous flooding; and use of a mechanical weeder – with those currently endorsed by the Central Rice Research Institute of India, referred to here as recommended management practices (RMP). All plots received the same fertilization, a combination of organic and inorganic nutrients, and the SRI spacing used was 20% less than usually recommended. Accordingly, the results reported here are designated as a modification of SRI recommendations (SRIm). The objective of this research was to understand the benefits in terms of yield and other physiological parameters, if any, from using most if not all recommended SRI practices compared to RMP. These selected SRI practices out-yielded RMP by 42%, with the higher yield associated with various phenotypical alterations, which are reported here. Significant measurable changes were observed in physiological processes and plant characteristics, such as longer panicles, more grains panicle−1 and higher % of grain-filling. The decreased plant density with SRIm management was compensated for by increased per-plant productivity. SRIm hills with single plants were found to have deeper and better-distributed root systems, higher xylem exudation rates, more open plant architecture with more erect and larger leaves, and more tillers than did RMP hills having multiple plants. Due to the reduction in number of hills m−2 in SRIm plots compared to RMP, no significant difference was found in root dry weight or leaf number, tillers or panicle number on an area basis. Nevertheless, in spite of SRIm having fewer hills and fewer tillers per unit area, the leaf area index (LAI) with SRIm practice was greater due to larger leaves. These together with altered plant architecture, contributed to more light interception by SRIm plants. The higher leaf chlorophyll content at ripening stage reflected delayed senescence and the greater fluorescence efficiency (Fv/Fm and ФPS II) associated with SRIm practices contributed to more efficient utilization of light and a higher rate of photosynthesis, which was probably responsible for the observed increase in grain filling and heavier grains compared to RMP plants. The higher photosynthesis rate coupled with lower transpiration in SRIm plants indicated that they were using water more efficiently than did RMP plants. The latter produced 1.6 μ mol CO2 fixed per m mol water transpired, compared to 3.6 μ mol CO2 in SRIm plants.

Field experiments were conducted in 2005 and 2006 to investigate the impacts of alternative rice cultivation systems on grain yield, water productivity, N uptake and N use efficiency (ANUE, agronomic N use efficiency; PFP, partial factor productivity of applied N). The trials compared the practices used with the system of rice intensification (SRI) and traditional flooding (TF). The effects of different N application rates (0, 80, 160 and 240 kg ha−1) and of N rates interacting with the cultivation system were also evaluated. Resulting grain yields with SRI ranged from 5.6 to 7.3 t ha−1, and from 4.1 to 6.4 t ha−1 under TF management. On average, grain yields under SRI were 21% higher in 2005 and 22% higher in 2006 than with TF. Compared with TF, SRI plots had higher harvest index across four fertilizer N rates in both years. However, there was no significance difference in above-ground biomass between two cultivation systems in either year. ANUE was increased significantly under SRI at 80 kg N ha−1 compared with TF, while at higher N application rates, ANUE with SRI was significantly lower than TF. Compared with TF, PFP under SRI was higher across all four N rates in both years, although the difference at 240 kg N ha−1 was not significant. As N rate increased, the ANUE and PFP under both SRI and TF significantly decreased. Reduction in irrigation water use with SRI was 40% in 2005 and 47% in 2006, and water use efficiency, both total and from irrigation, were significantly increased compared to TF. With both SRI and TF, the highest N application was associated with decreases in grain yield, N use efficiency and water use efficiency. This is an important finding given current debates whether N application rates in China are above the optimum, especially considering consequences for soil and water resources. Cultivation system, N rates and their interactions all produced significant differences in this study. Results confirmed that optimizing fertilizer N application rates under SRI is important to increase yield, N use efficiency and water use efficiency.

This four-year evaluation of the introduction of the System of Rice Intensification (SRI) in northern Myanmar through Farmer Field School (FFS) methods found that these agronomic and pedagogical strategies gave positive results in a complementary way, although their individual contributions to the documented improvement in rice productivity could not be partitioned. The rice production of 612 farmers who had participated in 30 FFSs was tracked, along with that of farmers in the same communities who learned through farmer-to-farmer interaction. Average SRI yields on FFS study-fields in the wet season, without any supplementary irrigation, were 6.4 t ha−1 compared with farmers' prior average yields of 2.1 t ha−1. Three years after one third of the farmers in a community had received FFS training, almost all of its farmers were using SRI methods. This study confirmed many previously reported benefits from SRI practices, particularly important for limited-resource households.

Efforts to protect vulnerable environmental resources have focused largely on legal prohibitions and sanctions or on economic rewards or penalties. The role and importance of social and cultural factors have been much less considered. While theoretical arguments have addressed whether state institutions must be involved in resource protection, or whether private incentives can be manipulated to achieve desired outcomes, this preoccupation with either public sector or private sector solutions to the problems of environmental conservation has caused a neglect of social values and community consensus. The analysis offered here seeks to enlarge the debate from being two-sided to three-cornered.

By bringing in a third set of considerations, the socio-cultural, the analysis underscores that individual decisions are embedded in community and local contexts. All three kinds of incentives are considered to be potentially of equal importance for resource-conserving behaviour (RCB) vis-à-vis resource-degrading behaviour (RDB). The analysis is concerned first with the strength of different incentives in favour of RCB compared to RDB, comparing legal and economic with socio-cultural considerations affecting RCB and RDB. Efforts to protect vulnerable resources can seek to alter in an RCB direction the attitudes and incentives of people along any or all of these three dimensions of motivation, or they can seek to make a particular domain of motivation more salient if it is supportive of environmental conservation.

This analysis is proposed in part to get the socio-cultural domain taken more seriously alongside the legal and economic domains, as well as to prompt more systematic consideration of different kinds of policies, investments, actions or pronouncements that could shift the net balance of incentives in favour of RCB. While the analysis is admittedly simplified, there is utility in encouraging focused comparisons and evaluations of conservation alternatives. Examples of efforts to promote RCB in Madagascar and Costa Rica are given to illustrate this.