Phosphorus Losses to Water from Lowland Rice Fields under Rice–Wheat Double Cropping System in the Tai Lake Region

Abstract. China's paddy rice accounts for about 22% of the world's rice fields, therefore it is crucial to accurately estimate the CH4 emissions at regional scale to gauge their contribution to global greenhouse gas effect. This paper reports an application of a biogeochemical model, DeNitrification and DeComposition or DNDC, for quantifying CH4 emissions from rice fields in Tai-Lake region of China by linking DNDC to a 1:50 000 soil database, which was derived from 1107 paddy soil profiles in the Second National Soil Survey of China in the 1980s–1990s. The modeled results estimate that the 2.34 M ha of paddy rice fields in Tai-Lake region emitted about CH4 of 5.67 Tg C for the period of 1982–2000, with the average CH4 flux ranged from 114 to 138 kg C ha−1y−1. The highest emission rate (659.24 kg C ha−1 y−1) occurred in the subgroup of "gleyed paddy soils", while the lowest (90.72 kg C ha−1y−1) were associated with the subgroup "degleyed paddy soils". The subgroup "hydromorphic paddy soils" accounted for about 52.82% of the total area of paddy soils, the largest of areas of all the soil subgroups, with the CH4 flux rate of 106.47 kg C ha−1y−1. On a sub-regional basis, the annual average CH4 flux in the Tai-Lake plain soil region and alluvial plain soil region was higher than that in low mountainous and hilly soil region and polder soil region. The model simulation was conducted with two databases using polygon or county as the basic unit. The county-based database contained soil information coarser than the polygon system built based on the 1:50 000 soil database. The modeled results with the two databases found similar spatial patterns CH4 emissions in Tai-Lake region. However, discrepancies exist between the results from the two methods, the relative deviation is −42.10% for the entire region, and the relative deviation ranged from −19.53% to 97.30% for most counties, which indicates that the more precise soil database was necessary to better simulate CH4 emissions from rice fields in Tai-Lake region using the DNDC model.

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Effects of soil spatial resolution on quantifying CH4and N2O emissions from rice fields in the Tai Lake region of China by DNDC model

Global Biogeochemical Cycles ◽

10.1029/2010gb003825 ◽

2011 ◽

Vol 25 (2) ◽

pp. n/a-n/a ◽

Cited By ~ 12

Author(s):

D. S. Yu ◽

H. Yang ◽

X. Z. Shi ◽

E. D. Warner ◽

L. M. Zhang ◽

...

Keyword(s):

Spatial Resolution ◽

Rice Fields ◽

N2o Emissions ◽

Dndc Model ◽

Lake Region ◽

Tai Lake

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Prevalence of Lowland Ecotype Cyperus rotundus L. and Weed Management of Rice Farmers in Aliaga, Nueva Ecija, Philippines

IAMURE International Journal of Ecology and Conservation ◽

10.7718/ijec.v13i1.855 ◽

2015 ◽

Vol 13 (1) ◽

Cited By ~ 1

Author(s):

DINDO KING M. DONAYRE ◽

EDWIN C. MARTIN ◽

MADONNA C. CASIMERO ◽

LEYLANI M. JULIANO ◽

JESUSA C. BELTRAN

Keyword(s):

Weed Management ◽

Upland Rice ◽

Management Practice ◽

Cropping System ◽

Rice Fields ◽

Lowland Rice ◽

Cyperus Rotundus ◽

Weed Species ◽

Cultivated Rice ◽

Rice Farmers

Cyperus rotundus L. was reported as dominant weed in upland rice areas and a minor problem in the rainfed lowland. However, it has evolved as second mostdominant weed in rainfed and irrigated lowland rice fields (rice-vegetable system) in three villages of San Jose City, Nueva Ecija. Its occurrence in the monoculture rice production system has never been explored especially in irrigated lowland rice fields of Nueva Ecija. Field surveys and interviews were conducted in 2005- 2006 to determine the prevalence of lowland ecotype C. rotundus and how farmers manage it in irrigated lowland rice fields of Aliaga, Nueva Ecija. In 2004, lowland rice fields of Nueva Ecija where the rice-rice cropping system was commonly established were surveyed. Aliaga was surveyed to calculate the incidence and map the distribution of the weed. To check whether C. rotundus was a problem, 40 randomly selected rice farmers were interviewed using a guided questionnaire. Results of the survey revealed that 9 of 26 villages in Aliaga had 1 - 10% infestation of C. rotundus; 3 had 11 - 20%; and 5 had more than 20%. Infestation was high in areas with low elevations. Even taller than cultivated rice, C. rotundus was the most commonly encountered and dominant weed species and had already existed for 5-20 years in the field. Herbicide application (MCPA at a rate of 1-1.5 L ha) was the most commonly used weed management practice against the weed. Keywords - Cyperus rotundus, weed control, herbicide, prevalence, farmers’ practices, ecotype, Nueva Ecija, Philippines

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Simulation of global warming potential (GWP) from rice fields in the Tai-Lake region, China by coupling 1:50,000 soil database with DNDC model

Atmospheric Environment ◽

10.1016/j.atmosenv.2009.02.051 ◽

2009 ◽

Vol 43 (17) ◽

pp. 2737-2746 ◽

Cited By ~ 26

Author(s):

Liming Zhang ◽

Dongsheng Yu ◽

Xuezheng Shi ◽

David C. Weindorf ◽

Limin Zhao ◽

...

Keyword(s):

Global Warming ◽

Global Warming Potential ◽

Rice Fields ◽

Dndc Model ◽

Soil Database ◽

Lake Region ◽

Tai Lake

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Suitable Maturity Period and Accumulated Temperature of Summer Maize in Wheat-maize Double Cropping System

ACTA AGRONOMICA SINICA ◽

10.3724/sp.j.1006.2018.00137 ◽

2018 ◽

Vol 44 (1) ◽

pp. 137

Author(s):

Bai-Zhao REN ◽

Fei GAO ◽

Yu-Jun WEI ◽

Shu-Ting DONG ◽

Bin ZHAO ◽

...

Keyword(s):

Cropping System ◽

Summer Maize ◽

Double Cropping ◽

Maturity Period ◽

Accumulated Temperature

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Effect of organic/inorganic compound fertilizer on the yield of crop and fodder double-cropping system in the Tibetan Plateau

CHINESE JOURNAL OF ECO-AGRICULTURE ◽

10.3724/sp.j.1011.2011.00568 ◽

2011 ◽

Vol 19 (3) ◽

pp. 568-573 ◽

Cited By ~ 1

Author(s):

Yong-Tao HE ◽

Wei SUN ◽

Xian-Zhou ZHANG ◽

Pei-Li SHI ◽

Cheng-Qun YU ◽

...

Keyword(s):

Tibetan Plateau ◽

Cropping System ◽

Inorganic Compound ◽

The Tibetan Plateau ◽

Double Cropping ◽

Compound Fertilizer

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Resource use efficiency in a cotton-wheat double-cropping system in the Yellow River Valley of China

Experimental Agriculture ◽

10.1017/s001447972000006x ◽

2020 ◽

Vol 56 (3) ◽

pp. 422-439

Author(s):

Guoping Wang ◽

Yabing Li ◽

Yingchun Han ◽

Zhanbiao Wang ◽

Beifang Yang ◽

...

Keyword(s):

Resource Use ◽

Yellow River ◽

Cropping Systems ◽

Cropping System ◽

River Valley ◽

The Yellow River ◽

Resource Use Efficiency ◽

Yellow River Valley ◽

Double Cropping ◽

Use Efficiency

AbstractThe cotton-wheat double-cropping system is widely used in the Yellow River Valley of China, but whether and how different planting patterns within cotton-wheat double-cropping systems impact heat and light use efficiency have not been well documented. A field experiment investigated the effects of the cropping system on crop productivity and the capture and use efficiency of heat and light in two fields differing in soil fertility. Three planting patterns, namely cotton intercropped with wheat (CIW), cotton directly seeded after wheat (CDW), and cotton transplanted after wheat (CTW), as well as one cotton monoculture (CM) system were used. Cotton-wheat double cropping significantly increased crop productivity and land equivalent ratios relative to the CM system in both fields. As a result of increased growing degree days (GDD), intercepted photosynthetically active radiation (IPAR), and photothermal product (PTP), the capture of light and heat in the double-cropping systems was compared with that in the CM system in both fields. With improved resource capture, the double-cropping systems exhibited a higher light and heat use efficiency according to thermal product efficiency, solar energy use efficiency (Eu), radiation use efficiency (RUE), and PTP use efficiency (PTPU). The cotton lint yield and biomass were not significantly correlated with RUE across cropping patterns, indicating that RUE does not limit cotton production. Among the double-cropping treatments, CDW had the lowest GDD, IPAR, and PTP values but the highest heat and light resource use efficiency and highest overall resource use efficiency. This good performance was even more obvious in the high-fertility field. Therefore, we encourage the expanded use of CDW in the Yellow River Valley, especially in fields with high fertility, given the high productivity and resource use efficiency of this system. Moreover, the use of agronomic practices involving a reasonably close planting density, optimized irrigation and nutrient supply, and the application of new short-season varieties of cotton or wheat can potentially enhance CDW crop yields and productivity.

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