The regime and P availability of omitting P fertilizer application for rice in rice/wheat rotation in the Taihu Lake Region of southern China

This study was conducted on a P-deficient Dark Grey Solod to compare the effects of the rate (0, 45, 90 kg P ha−1 cumulative), placement method (broadcast vs. banding), and frequency (preplant only vs. annually) of P fertilizer application on herbage production by a bromegrass (Bromus inermiss Leyss)–red clover (Trifolium pratense L.) mixture. The preplant broadcast application was incorporated by rototilling, and subsequent broadcast applications were topdressings. Annual applications continued for 3 yr only and dry matter (DM) yields were taken for 4 yr following the establishment year in 1991. Rate of P applied had the greatest effect on herbage yield, but its effect was influenced by the frequency of application. When P fertilizer was applied annually, herbage yields increased linearly with application rates. When P was applied preplant only, herbage yields reached a plateau with 45 or more kg P ha−1. Broadcasted P yielded slightly more than banded-in P in the first year harvest only. Annual application of 30 kg P ha−1 gave the highest cumulative herbage yield, suggesting decreasing P availability with time. This was supported by soil P analysis in 1994 and by herbage P concentrations. Herbage P concentration was significantly correlated with herbage yields of the second year and subsequent harvests. It is concluded that a preplant broadcast-incorporated application of 30 to 45 kg P ha–1, followed by at least one subsequent surface application of 30 kg P ha–1 was required for optimum herbage production by a legume-grass mixture. Key words: Application method, P fertilizer management, bromegrass-red clover, Grey Luvisol, soil P distribution

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Effect of Irrigated Crop Rotation and Phosphorus Fertilizer-Manure on Soil Water Repellency of a Clay Loam Soil in Southern Alberta

Canadian Journal of Soil Science ◽

10.1139/cjss-2021-0067 ◽

2021 ◽

Author(s):

Jim J. Miller ◽

Mallory Owen ◽

Ben Ellert ◽

Xueming Yang ◽

Craig F. Drury ◽

...

Keyword(s):

Soil Water ◽

Water Repellency ◽

Fertilizer Application ◽

Clay Loam ◽

P Fertilization ◽

Soil Water Repellency ◽

Hydrophobic Coatings ◽

Southern Alberta ◽

P Fertilizer ◽

Loam Soil

Soil water repellency (SWR) was measured for a 28 yr field study under irrigation on a clay loam Dark Brown soil in southern Alberta. The objectives were to study the effect of legume-cereal crop rotations, feedlot manure, and phosphorus (P) fertilizer application on soil hydrophobicity (SH) and soil water repellency index (RI) under irrigation. Mean SH and RI were similar (P > 0.05) for a legume-cereal and cereal rotation, and were unaffected by P fertilization. However, P fertilization shifted the RI classification from slight to sub-critical. In contrast, SH was significantly greater for manured than non-manured treatments, while RI was unaffected. Soil organic carbon (SOC) concentration was significantly (P ≤ 0.05) correlated with SH (r=0.74), but not with RI (r=-0.17). This suggested a closer association between the quantity of SOC and quantity of hydrophobic compounds (SH method) compared to the hydrophobic coatings inhibiting infiltration of water (RI method). No significant correlation between SH and RI (r=-0.09) suggests that SH is not a good predictor of SWR using the RI method. Overall, manure application increased SH and P fertilization shifted the RI classification from slight to sub-critical. In contrast, legume-cereal rotations had no influence on SH and SWR using RI method compared to continuous cereal.

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Life-cycle evaluation of nitrogen-use in rice-farming systems: implications for economically-optimal nitrogen rates

Biogeosciences ◽

10.5194/bg-8-3159-2011 ◽

2011 ◽

Vol 8 (11) ◽

pp. 3159-3168 ◽

Cited By ~ 15

Author(s):

Y. Xia ◽

X. Yan

Keyword(s):

Life Cycle ◽

Environmental Impact ◽

Taihu Lake ◽

Oryza Sativa L ◽

Growing Season ◽

Economic Effects ◽

N Fertilizer ◽

Environmental Cost ◽

N Losses ◽

Lake Region

Abstract. Nitrogen (N) fertilizer plays an important role in agricultural systems in terms of food yield. However, N application rates (NARs) are often overestimated over the rice (Oryza sativa L.) growing season in the Taihu Lake region of China. This is largely because negative externalities are not entirely included when evaluating economically-optimal nitrogen rate (EONR), such as only individual N losses are taken into account, or the inventory flows of reactive N have been limited solely to the farming process when evaluating environmental and economic effects of N fertilizer. This study integrates important material and energy flows resulting from N use into a rice agricultural inventory that constitutes the hub of the life-cycle assessment (LCA) method. An economic evaluation is used to determine an environmental and economic NAR for the Taihu Lake region. The analysis reveals that production and exploitation processes consume the largest proportion of resources, accounting for 77.2 % and 22.3 % of total resources, respectively. Regarding environmental impact, global warming creates the highest cost with contributions stemming mostly from fertilizer production and farming processes. Farming process incurs the biggest environmental impact of the three environmental impact categories considered, whereas transportation has a much smaller effect. When taking account of resource consumption and environmental cost, the marginal benefit of 1 kg rice would decrease from 2.4 to only 1.05 yuan. Accordingly, our current EONR has been evaluated at 187 kg N ha−1 for a single rice-growing season. This could enhance profitability, as well as reduce the N losses associated with rice growing.

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Effects of agricultural production on phosphorus losses from paddy soils: a case study in the Taihu Lake Region of China

Wetlands Ecology and Management ◽

10.1007/s11273-003-5033-8 ◽

2005 ◽

Vol 13 (1) ◽

pp. 25-33 ◽

Cited By ~ 11

Author(s):

Huanchao Zhang ◽

Fuliang Cao ◽

Shengzuo Fang ◽

Gaiping Wang ◽

Hongai Zhang ◽

...

Keyword(s):

Agricultural Production ◽

Taihu Lake ◽

Paddy Soils ◽

Lake Region ◽

Phosphorus Losses

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Influence of intra-row plant spacing, phosphorus application and growth stage on the forage, seed yields and quality of phasey bean (Macroptilium lathyroides) in subhumid area of Nigeria

Nigerian Journal of Animal Production ◽

10.51791/njap.v31i1.1456 ◽

2021 ◽

Vol 31 (1) ◽

pp. 45-50

Author(s):

A. T. Omokanye ◽

J. T. Amodu ◽

S. O. Onifade

Keyword(s):

Production Systems ◽

Fertilizer Application ◽

Plant Spacing ◽

Growing Seasons ◽

Application Rates ◽

P Fertilizer ◽

P Application ◽

Macroptilium Lathyroides ◽

Seed Yields ◽

Phosphorus Application

Forage, seed yields and herbage chemical composition of phasey bean Macroptilium lathyroides) were investigated at 3 intra-row plant spacings (15, 30 and 45cm between plants; 50 cm between roms), 4 phosphorus (P) fertilizer application rates (O), 50, 100 and 750 kg/ha P) and 5 harvest stages (uncut control, 6, 9, 12 and 15 weeks post sowing) in two growing seasons at Shika in northern Nigeria. The least intra-row plant spacing (15cm) produced higher (p<0.01) total DM vield (1.50 t/ha) than wider spacings. The proportion of leaf was least (40 %) in the widest spacing compared with other spacings (59-62 %). The P-fertilized plots produced 58-60% more total DM vields than the unfertilized plots and total DM yields increased with advanced plant growth. The highest percentage (61-63) of leaf was recorded from 6 to 12 weeks post sowing. Nitrogen level in herbage increased (p<0.05) with increased intra-row plant spacing and P application. Phosphorus and Calcium. Levels in herbage did not respond to intra-row plant spacing but increased with P application. The Ca:P ratios at the harvest stages were between 1:1 and 6:1. The highest seed yields (198 and 188 kg/ha) were recorded respectiely in the least intra-row plant spacing and the application of 100 kg Piha. Supplementation of calves on grasses/cereal stovers with phasey bean hay in a sustainable crop livestock production systems is suggested.

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