Most of the aromatic rice cultivars are susceptible to disease, insect-pest attack and are more prone to lodging. Therefore, nitrogen is the key input for increasing the productivity of aromatic rice. Research analyzi...Most of the aromatic rice cultivars are susceptible to disease, insect-pest attack and are more prone to lodging. Therefore, nitrogen is the key input for increasing the productivity of aromatic rice. Research analyzing the effects of N level on yield and quality characteristics of modem aromatic cultivars in the north-western Indo-Gangetic Plains is not well documented. Therefore, the present study was conducted to optimise the N levels for higher yield and better quality of the modem aromatic rice cultivars. The mean grain yield increased by 22.5% when plots were supplemented with 40 kg/ha of N application as compared to control （unfertilized）. Among cultivars, Punjab Mehak 1 registered highest yield （5.3 t/ha） followed by Pusa Basmati 1121 （4.78 t/ha） and Punjab Basmati 2 （4.66 t/ha） respectively. Interactive effect between N levels and cultivars on grain yield revealed that in Punjab Mehak l, grain yield responded significantly up to 60 kg/ha of N application as compared to Pusa Basmati 1121 and Punjab Basmati 2 where it responded only upto 40 kg/ha of N application. All the quality characteristic found to be improved with N application, whereas amylose content decreased with 60 kg/ha of N application as compared to 20 and 40 kg/ha of N application.展开更多
As a result of intensive greenhouse vegetable production in northern China, the potential risk of nitrogen （N） fertilizer over-applied is increasingly apparent and is threatening ecosystem and the sustainability of ...As a result of intensive greenhouse vegetable production in northern China, the potential risk of nitrogen （N） fertilizer over-applied is increasingly apparent and is threatening ecosystem and the sustainability of food production. An experiment was carried out in Shouguang, Shangdong Province, China to evaluate agronomic benefit and soil quality under different N applications, including the conventional chemical N rate （1000 kg N ha^（-1） season^（-1）, N1）, 70% of N1 （N2）, 70% of N1 ＋ maize straw （N3）, 50% of N1 ＋ maize straw ＋ drip irrigation （N4）, and 0% of N1 （NO）, during two successive growing seasons of autumn-winter （AW） and winter-spring （WS）. The maximum yields for N4 were 1.1 and 1.0 times greater than those for N1 in the AW and WS seasons, respectively. N agronomic efficiency （AEN） and apparent N recovery efficiency （REN） were greatest with the N4. A significant relationship was found between soil NO3-N content and electrical conductivity （EC） （R^2 = 0.61 in the AW season and R^2= 0.29 in the WS season）. Reducing N fertilizer decreased soil NO3-N accumulation （20.9%-37.8% reduction in the AW season and 11.7%-20.1% reduction in the WS season） relative to the accumulation observed for N1 within the 0-100 cm soil layer. Soil urease and invertase activities were not significantly different among N treatments. The N4 treatment would be practical for reducing excess N input and maintaining the sustainability of greenhouse-based intensive vegetable systems in Shouguang.展开更多
文摘Most of the aromatic rice cultivars are susceptible to disease, insect-pest attack and are more prone to lodging. Therefore, nitrogen is the key input for increasing the productivity of aromatic rice. Research analyzing the effects of N level on yield and quality characteristics of modem aromatic cultivars in the north-western Indo-Gangetic Plains is not well documented. Therefore, the present study was conducted to optimise the N levels for higher yield and better quality of the modem aromatic rice cultivars. The mean grain yield increased by 22.5% when plots were supplemented with 40 kg/ha of N application as compared to control （unfertilized）. Among cultivars, Punjab Mehak 1 registered highest yield （5.3 t/ha） followed by Pusa Basmati 1121 （4.78 t/ha） and Punjab Basmati 2 （4.66 t/ha） respectively. Interactive effect between N levels and cultivars on grain yield revealed that in Punjab Mehak l, grain yield responded significantly up to 60 kg/ha of N application as compared to Pusa Basmati 1121 and Punjab Basmati 2 where it responded only upto 40 kg/ha of N application. All the quality characteristic found to be improved with N application, whereas amylose content decreased with 60 kg/ha of N application as compared to 20 and 40 kg/ha of N application.
基金the National Natural Science Foundation of China (No.21107139)the Ministry of Agriculture Public Benefit Research Foundation of China (No.201103007)+1 种基金the Special Fund of Research Institute Technology Development of China (No.2012EG134235)the National Basic Research Program (973 program) of China (No.2007CB109308)
文摘As a result of intensive greenhouse vegetable production in northern China, the potential risk of nitrogen （N） fertilizer over-applied is increasingly apparent and is threatening ecosystem and the sustainability of food production. An experiment was carried out in Shouguang, Shangdong Province, China to evaluate agronomic benefit and soil quality under different N applications, including the conventional chemical N rate （1000 kg N ha^（-1） season^（-1）, N1）, 70% of N1 （N2）, 70% of N1 ＋ maize straw （N3）, 50% of N1 ＋ maize straw ＋ drip irrigation （N4）, and 0% of N1 （NO）, during two successive growing seasons of autumn-winter （AW） and winter-spring （WS）. The maximum yields for N4 were 1.1 and 1.0 times greater than those for N1 in the AW and WS seasons, respectively. N agronomic efficiency （AEN） and apparent N recovery efficiency （REN） were greatest with the N4. A significant relationship was found between soil NO3-N content and electrical conductivity （EC） （R^2 = 0.61 in the AW season and R^2= 0.29 in the WS season）. Reducing N fertilizer decreased soil NO3-N accumulation （20.9%-37.8% reduction in the AW season and 11.7%-20.1% reduction in the WS season） relative to the accumulation observed for N1 within the 0-100 cm soil layer. Soil urease and invertase activities were not significantly different among N treatments. The N4 treatment would be practical for reducing excess N input and maintaining the sustainability of greenhouse-based intensive vegetable systems in Shouguang.
