Application Of Liquid Pig Manure Research Articles

Co-application of fly ash and zeolite increases N uptake but decreases P uptake and biomass of rice fertilized with fermented liquid manure

ABSTRACT Fermented liquid pig manure (LPM) can be used as a nutrient source to replace synthetic fertilizers (SF). However, concerns remain regarding nitrogen (N) and phosphorus (P) losses from rice (Oryza sativa L.) paddies fertilized with LPM. Fly ash (FA) has a high calcium content (Ca) and zeolite (Z) has a high negative-charge; thus, they can immobilize P and N through the fixation of P with Ca and NH4 + onto negatively charged sites, respectively. This study investigated the effects of the co-application of FA and Z (FAZ) on the nutrient availability and growth of rice fertilized with LPM. Four treatments were evaluated: no input (control), synthetic fertilizer (SF), and LPM at two levels, with or without FAZ application, for 104 days. The pH (pHwater), electrical conductivity (ECwater), N (Nwater), and P (Pwater) concentrations in the ponding water of rice fields were analyzed 18 times during rice growth. The rice biomass and uptake of N and P were measured, and the concentrations of mineral N and available P in soil were determined after harvest. LPM application increased (p < 0.001) N and P availability in the absence of FAZ, leading to rice biomass comparable to that of SF. However, FAZ diminished the fertilization effects of LPM on rice growth. The Nwater decreased by 50% and the rice uptake of N increased by 6% after FAZ application, probably because of the retention of N by Z and its subsequent release. By contrast, FAZ increased (p < 0.001) soluble Pwater (85% for LPMS) and decreased (p = 0.004) P uptake (8%–40%), reducing the rice biomass by 20%–25%. The decreased P uptake is probably due to the strong immobilization of P by FA. Therefore, it is cautioned that P-limitation through immobilization of P by FA under alkaline conditions may hinder rice growth in FAZ-amended paddy fertilized with LPM. An appropriate application rate of FA for improved P nutrition needs to be explored.

Weed community dynamics under repeated fertilization with different nutrient sources over 5 years

Soil fertility management through the application of synthetic fertilizer or livestock manures is crucial to maintaining the productivity and profitability of cropping systems. Little, however, is known about the response of weed communities to different livestock manure nutrient sources. As weed communities with increased diversity are considered part of more sustainable agroecosystems, it is necessary to find management practices that result in diverse weed communities of acceptable densities without negative impacts on crop productivity. Here, we monitored the effect of five nutrient sources, with similar goals for nitrogen (N) management, including synthetic fertilizer, liquid pig manure, two types of solid pig manure, and solid dairy manure on the weed community in a five-year (2008-2012) study. The abundance, species richness, Simpson’s diversity, Simpson’s evenness, and species turnover in weed communities were assessed over time. Crop biomass, mid-season plant-accessible soil nitrate-N, and pre-season soil phosphorus were determined. The application of liquid pig manure or synthetic fertilizer enhanced crop biomass likely through increased crop accessibility to N. The continued use of these sources of nutrients over time, contributed to low density, low species richness, and low diversity weed communities, particularly through the decline of broadleaf weed species. Liquid pig manure and synthetic fertilizer treatments were lower in weed density and diversity than solid manures. Solid manure treatments were associated with increased weed densities and reduced crop biomass; however, these nutrient source treatments resulted in more diverse weed communities. Regardless of the nutrient treatments, we observed drastic declines in weed community abundance, species richness, and diversity in drier years. Our study suggests that a management practice that increases the accessibility of N to the crop, possibly through a mixture of solid manures and synthetic fertilizers or liquid pig manure, may be ideal for promoting a profitable cropping system with decreased densities and improved diversity in weed communities. Technological advances that provide more precise placement of solid manures to increase the accessibility of N to the crop, may further contribute to achieving such profitable and multifunctional agroecosystems.

Impact of surface-applied liquid manure on the drainage resistance profile of an agricultural tile-drained clay till field.

Dissemination of antibiotic resistance genes (ARGs) in aquatic environments is a concern due to human and animal health. Application of liquid manure on agricultural land is an important source of ARGs, where pathogens, antibiotic-resistant bacteria, and selective agents are released. To improve our understanding of ARGs spreading through soils, our main objective was to evaluate the effectiveness of the soil as a barrier protecting water resources. Over the course of a year, profiles and abundances of ARGs and mobile genetic elements in soil and drainage from an agricultural tile-drained clay till field were investigated upon liquid pig manure application by applying high-throughput quantitative polymerase chain reaction targeting 143 genes. The findings were as follows: (a) 97 genes were detected, where only the transposon gene tnpA-03/ IS6 was shared between the genes detected in drainage and those in acidified liquid manure or fertilized soils, indicating that liquid manure application had a limited impact on the drainage resistance profile; (b) intI1 gene was present in ∼60% of drainage samples in concentrations up to 1,634intI1 ml-1 ; and (c) evapotranspiration from barley (Hordeum vulgare L., 'KWS Irina') and a low groundwater table appeared to reduce preferential transport to drainage during the first 3 mo of liquid manure application. Interestingly, the first preferential transport to drainage was observed immediately after the harvest of spring barley. Overall, during the monitoring year we found the soil to be an effective barrier against the spread of fecal ARGs even though the occurrence of the intI1 gene questions the barrier effect from previous years.

Utilization of liquid pig manure for resource cycling agriculture in rice-green manure crop rotation in South Korea.

A 2-year field experiment was carried out on rice (Oryza sativa, Japonica type) cultivation in South Korea. The objective of this study was to investigate the effect of application of liquid pig manure on biomass production and nutrient supply of green barley (Hordeum vulgare L.) and hairy vetch (Vicia villosa Roth) green manure crops and to evaluate the effect of nutrients supplied from these sources on rice yield and soil quality in a rice-green manure crop rotation system. Over the 2-year study period, application of liquid pig manure increased biomass production of green manure crops of barley and hairy vetch by more than 216% and 135%, respectively, compared with without liquid pig manure. Moreover, the results showed that the application of liquid pig manure significantly increased the nutrient supply levels in green barley- and hairy vetch-treated areas. Positive effects related to nutrient supply in green barley and hairy vetch treated with liquid pig manure were observed on rice yield, soil chemical characteristics, and microbial biomass C and N contents. In conclusion, the addition of liquid pig manure systems using green manure crops of green barley and hairy vetch improved rice productivity and soil quality. It is suggested that these combinations can be effective in developing resource cycling agriculture in a rice-green manure crop rotation system as it reduces the need for inorganic fertilizer.

Damages of Young Persimmon Tree as Affected by Application of Immature Liquid Pig Manure

BACKGROUND: Liquid pig manure (LPM) has been used as an alternative for conventional fertilizers on some gramineous crops. However, its chemical properties varied widely depending on the degree of the digestion. A pot experiment was conducted to determine the responses of persimmon trees to immature (not well-digested) LPM application. METHODS AND RESULTS: Ten application levels of immature LPM, consisted of a total of 3 to 30 L in 3-L increment, were applied during summer to 5-year-old ‘Fuyu’ trees grown in 50-L pots. Increasing the LPM application rate caused defoliation, wilting, and chlorosis in leaves. When applied with the rate of 3 L during summer, the tree produced small fruits with low soluble solids and bore few flower buds the following season, indicating insufficient nutritional status. In trees applied with the LPM rates of 6∼12 L, both fruit characteristics and aboveground growth of the trees appeared normal but some roots were injured. However, application of higher LPM rates than 27 L resulted in small size, poor coloration, or flesh softening of the fruits the current season. Furthermore, the high LPM rates caused severe cold injury in shoots during winter and weak shoot growth the following season. It was noted that the application of higher LPM rate than 9 L damaged the root, even though above-ground parts of the tree appeared to grow normally. CONCLUSION: The results indicated that an excessive immature LPM application could cause various injuries on leaves, fruits, and the roots in both the current and the following season.

Disentangling the effects of the aqueous matrix on the potential toxicity of liquid pig manure in sub-tropical soils under semi-field conditions

Inadequate application of liquid pig manure (LPM) may pose risks to the soil due to the potential contaminants that exists, as well as by the large water input that can originate excessive moisture. By using Terrestrial Model Ecosystems, this study aimed to evaluate the effect of application of LPM (82% moisture) using the application rates of 20, 50 and 150 m3 ha−1 and also of the corresponding amount of water to understand the origin of effects on the soil fauna of two sub-tropical soils. In general, the results obtained for the two soil types indicated that LPM (150 m3 ha−1) changed the composition of soil fauna, with an increase in the abundance of insect larvae and dipterans, but a decrease in the number of earthworms and enchytraeids. Microbial biomass, soil respiration and the nutrients Mg, K and P increased with the amount of LPM supplied to the soil. When analysing the effects of adding large volumes of water via the LPM, results showed that application did not originate significant effects on the parameters measured. The differences obtained when comparing both treatments were mainly attributed to the organic load brought by the LPM and not to the amount of water without LPM.

Cropping System and Type of Pig Manure Affect Nitrate-Nitrogen Leaching in a Sandy Loam Soil.

The application of livestock manure can result in the loss of nitrate-nitrogen (NO-N) and degrade surface and groundwater. A 3-yr lysimeter study was set up to compare the effect of cropping system and nitrogen (N)- and phosphorus (P)-based pig manure application rates on the loss of water and NO-N below the root zone. The experiment was a split-plot design with annual and perennial cropping systems as the main factor. Five nutrient management treatments were the subplots: N-based liquid pig manure application; P-based liquid pig manure application, N-based solid pig manure application, P-based solid pig manure application, and a control without amendment. The results showed that 40 to 60 kg NO-N ha was lost from the annual plots in 2010 and 23 to 60 kg NO-N ha in 2011, whereas a negligible amount of NO-N was lost from the perennial (<1 kg ha) plots in both years. The application of solid pig manure on a P basis followed by urea in subsequent years reduced the risk of NO-N leaching over the course of the rotation, likely due to immobilization of N by the straw in the solid pig manure. Our study showed that a perennial cropping system consisting of a mixture of grasses has the capacity to receive and utilize significant amounts of nutrients with negligible amount of nutrient leakages to the adjacent environment. The inclusion of grasses in a crop rotation and their use to take up excess nutrients are sustainable practices that will benefit the environment.

Effects of Liquid Pig Manure on Yield and Nutrition Supply of Green Manure Crops in Jeju

The effects of liquid pig manure (LPM) on the yield and nutrient supply of green manure crops, such as hairy vetch alone and hairy vetch + rye mixture, were investigated. We used three treatments: no-fertilizer (NF); LPM, <TEX>$4.0t10a^{-1}$</TEX> (<TEX>$N-P_2O_5-K_2O=4.0-0.024-4.0kg10a^{-1}$</TEX>); and chemical fertilizer (CF; <TEX>$N-P_2O_5-K_2O=4.0-0-4.0kg10a^{-1}$</TEX>). The green manure crops, namely, Vicia villosa Roth. (hairy vetch) and Secale cereale L. (rye). were sown on March 11 and harvested on June 24, 2014. Yield of green manure crops significantly increased in hairy vetch + rye mixture plot compared with the hairy vetch alone plot. In hairy vetch alone plot, yield of green manure crops was increased by application of LPM and CF, but there were no significant differences. Yield of green manure crops in hairy vetch + rye fresh mixture plot significantly increased by the LPM and CF treatments, but no difference was noted between the LPM and CF treatments. Nitrogen supply by the green manure crops was higher in hairy vetch + rye mixture plot than hairy vetch alone plot. However, there was no significant difference. Phosphorus and potassium supply significantly increased in hairy vetch + rye mixture plot compared with hairy vetch alone plot. By treating LPM and CF, the nitrogen, phosphorus and potassium supply were higher than those in no fertilizer. In conclusion, LPM could replace CF. When planting green manure crops, the hairy vetch + rye mixture was more effective than hairy vetch alone to effectively use green manure crops.

Effects of Liquid Pig Manure Application Level on Growth Characteristics, Yield, and Feed Value of Whole Crop Barley at Reclaimed Tidal Land in Southwestern Korea

This study was conducted to investigate liquid pig manure (LPM) application rates on the growth characteristics, yield, and feed value of whole crop barley in Yeongsangang and Saemangeum reclaimed tidal land. Electronic conductivity (EC), organic matter (OM), and available phosphate (Av. P₂O 5 ) increased in chemical properties of Yeongsangang and Saemangeum soil as raising LPM application level. As increasing LPM application level, exchangeable Na+ significantly increased in Yeongsangang, while exchangeable K+ significantly increased in Saemangeum. Plant height was not significantly different from LPM 100% to LPM 200% in Yeongsangang and in Saemangeum. Dry matter yield of whole crop barley increased steadily, but crop yield of LPM 200% in Yeongsangang (10.5 ton ha -1 ) was as much as that of LPM 150% (10.0 ton ha -1 ). Yield of LPM 200% (11.2 ton ha -1 ) in Saemangeum was similar to that of LPM 150% (10.5 ton ha -1 ). Crude protein (CP) increased depending on LPM application level, but total digestible nutrients (TDN) increased regardless of LPM application level. LPM 200% was the highest in TDN yield (Yeongsangang: 7.4 ton ha -1 , Saemangeum: 6.9 ton ha -1 ), but there was no statistical difference between LPM 150% (Yeongsangang: 6.9 ton ha -1 , Saemangeum: 6.6 ton ha -1 ) and LPM 200%. From the results described above, optimum rate of LPM for cultivating whole crop barley is considered 100% in Yeongsangang reclaimed tidal land and 150% in Saemangeum reclaimed tidal land, showing that the effect of LPM application is better in Segmentation than that in Yeongsangang for yield of whole crop barley.

돈분액비 시용이 트리티케일 생육과 토양의 화학적 특성에 미치는 영향

돈분액비 시용이 트리티케일 생육과 토양의 화학적 특성에 미치는 영향

Impacts of Pig Manure-Based Liquid Fertilizer Agricultural Application on the Water Quality of Agricultural Catchment

This study was conducted to understand the effect of the livestock liquid fertilizer treatment at field-scale up to catchment-scale on the water quality properties. Cultivated paddy rice and upland plots located in Gyeonggi province, Korea were treated with two different liquid fertilizers, SP (Liquid fertilizer with storage process) and SCB (Liquid fertilizer with slurry composting and bio-filtration process). Plots with no fertilizer (control A) and chemical fertilizer (control B) were also prepared for comparison. Water quantity and quality were monitored at the catchment outlet for assessing the effect on water quality of stream water. As a result, the losses of N and P and the values of EC (Electronic Conductivity) in the surface drainage water from paddy rice plots treated with SP and SCB were higher than those from the control plots (A and B). In addition, the losses of N and P by the runoff water from upland plots with SP and SCB treatment were higher than those from control plots (A and B). The nutrient outflow from paddy rice fields and uplands with application of liquid pig manure was higher than those from the control plots (A and B). Particularly, the outflow from uplands may directly affect the water quality in neighboring streams. This caused the major eutrophication problem in stream water. In conclusion, it is necessary to establish the proper management practices to prevent the nutrient losses from agricultural fields and the pollutants against water environments.

청보리와 헤어리베치 단작 및 혼작 재배지에서 돈분액비 시용이 녹비생산량에 미치는 영향

본 논문은 청보리와 헤어리베치 단작 및 혼작 재배지에서 돈분액비 시용이 녹비의 생육과 biomass에 미치는 영향을 조사하였다. 단작 재배지에서 녹비작물의 초장은 LPM 3.3 처리구에서 가장 길었으며, 혼작 재배지에서는 LPM 6.6 처리구에서 가장 길었다. 단작 재배지에서 녹비작물의 biomass는 질소 시비량의 전량 100%에 해당하는 LPM 3.3 처리구에서 최대생육을 나타냈으며, 질소 시비량의 전량 200%에 해당하는 LPM 6.6은 돈분액비의 과잉시용으로 인해 biomass가 낮게 조사된 것으로 판단된다. 혼작 재배지에서는 질소 시비량의 전량 200%에 해당하는 LPM 6.6 처리구가 LPM 3.3 처리구에 비해 높은 biomass를 나타내었으며, 이는 단작 재배와 달리 혼작 재배에서는 청보리 및 헤어리베치의 양분 요구도가 증가했기 때문이라고 판단된다. 따라서 돈분액비 최적 투입량은 청보리와 헤어리베치 단작재배의 경우 <TEX>$3.30Mg\;10a^{-1}$</TEX> 정도이었고, 청보리와 헤어리베치 혼작재배의 경우 <TEX>$6.60Mg\;10a^{-1}$</TEX> 정도이었다. To evaluate the effects of liquid pig manure (LPM) on green manure crop yields, plant height and biomass of green manure crops were investigated in single and companion cropping. Green manure crops used for this experiment were Hordeum vulgare L. (green barley) and Vicia villosa roth (hairy vetch). Field experiment was designed with LPM 1.65 (LPM of <TEX>$1.65ton\;10a^{-1}$</TEX> + single and companion green crops), LPM 3.3 (LPM of <TEX>$3.3ton\;10a^{-1}$</TEX> + single and companion green crops) and LPM 6.6 (LPM of 6.6<TEX>$6.6ton\;10a^{-1}$</TEX> + single and companion green crops). In single cropping, plant height were high in LPM 3.3. In companion cropping, plant height were high in LPM 6.6. Thus, we found that application of LPM is general enough to reduce use of chemical fertilizer. Also, optimum application level in single cropping would be LPM 3.3 and in companion cropping would be higher than LPM 3.3.

돈분액비 연용 농경지 중 중금속 함량 모니터링

본 연구에서는 돈분 액비를 연용한 논토양 및 밭토양의 유해 중금속을 관리하는 방안을 마련하고자 전국적으로 액비를 장기 시용한 연차별 논토양 41점과 밭토양 54점을 채취하여 유해 중금속인 카드뮴, 구리, 니켈, 납, 아연, 비소의 함량을 조사하였다. 액비연용에 따른 년차별 변화에서 논토양 및 밭토양 중금속 전함량은 원소별로 일부 증가하는 경향은 보이나 연도별 축적 차이를 통계적으로 확인할 수 없었다. 그러나 액비연용에 따른 중금속 특히 구리 및 아연의 축적 여부는 이들이 식물영양에 필수 원소로 작용함을 고려하여 보다 장기적인 관점으로 계속 검토되어야 할 사항이다. 그러나 일부 밭토양에서 토양오염 우려기준을 초과하는 지점이 조사되어 액비 시용 전 토양 내 중금속 함량조사를 통해 시용 여부를 결정하여야 할 것이다. BACKGROUND: Increase of heavy metals in agricultural ecosystem has become a social issue nationwide as it is related to public health. This study was performed to find out the status and long-term trends with consecutive application with the commercial liquid pig manure in the agricultural fields. METHODS AND RESULTS: Heavy metals including arsenic, cadmium, copper, lead, nickel, and zinc were analyzed in the 41 samples of paddy fields and 54 samples of upland fields consecutively applied with commercial liquid pig manure for 0 to 16 years. Heavy metal accumulation were not increased statistically at the both paddy and upland fields as the consecutive application year of commercial liquid pig manure were increased. However, some of surveyed upland soils exceeded the criteria of cadmium, copper, and zinc designated by the Soil Environmental Conservation Act in Korea. CONCLUSION: Therefore, analysis of heavy metals, specially copper and zinc, in agricultural fields is absolutely necessary before liquid pig manure application to the fields. In addition, heavy metal accumulation in agricultural fields following to the long-term application of liquid pig manure will be monitored periodically considering with bioavailability of copper and zinc to the crops as an essential nutrients.

벼-자운영 윤작재배에서 돈분액비 시용이 토양화학성에 미치는 영향

This study was conducted to investigate the effect of liquid pig manure application on soil chemical properties in rice - Chinese milkvetch rotation. Field experiment was designed with APLM 0 (Chinese milkvetch + Liquid pig manure ), APLM 50 (Chinese milkvetch + Liquid pig manure ), APLM 75 (Chinese milkvetch + Liquid pig manure ) and APLM 100 (Chinese milkvetch + Liquid pig manure ), respectively. The concentration of O.M, T-N, Avail. , K, Ca and Mg at different liquid pig manure levels in soil were generally high in the order of APLM 100 > APLM 75 > APLM 50 > APLM 0. Especially, T-N concentration of soil in APLM 100 was 1.4 times higher than APLM 0. The yield of rice in APLM 100 was (increasing yield 5.3%) compared with APLM 0 in rice-Chinese milkvetch crop rotation. Therefore, application of liquid pig manure was useful in rice - Chinese milkvetch crop rotation.

돈분뇨 시용 후 담수시기가 암모니아 휘산에 미치는 영향

본 연구는 논에서 돈분 액비 활용시 담수 시기에 따른 암모니아 휘산량을 평가하였다. 담수 상태에서 돈분 액비 시용은 142.0 mg/<TEX>$m^2$</TEX> 의 암모니아 휘산량을 보인 반면, 돈분액비시용 1일 및 3일 후 담수시 암모니아 휘산량은 29.6, 25.4 mg/<TEX>$m^2$</TEX> 였다. 그리고 담수 상태에서 돈분액비 시용이 돈분액비 시용 후 담수에 비해 높은 암모니아 휘산량을 보인 것은 암모니아가 토양교질에 흡착되지 않고 수중에 높은 농도로 존재하기 때문인 것으로 나타났다. 따라서 논에서 돈비 액비 활용시 암모니아 휘산량 저감에 의한 질소 이용도 향상을 위해서는 돈분액비 살포 최소 1일 후 담수하는 것이 좋을 것으로 판단된다. BACKGROUND: Ammonia emissions from field-applied livestock manure are considered a threat to the environment worldwide. In Korea, a large amount of liquid manure was applied in the rice field before rice transplanting in order to reduce chemical fertilizer use. This study was conducted to provide the optimal flooding time after liquid manure application in an attempt to minimize ammonia emission. METHODS AND RESULTS: Ammonia emission from paddy field applied with liquid pig manure following different flooding time was measured using the dynamic chamber method. The five treatments used were : application of liquid pig manure to paddy field in flooding condition (F0T); one day (F1T) and three days (F3T) after flooding; without flooding (NF), and flooding without the application of liquid pig manure (control). Among the treatment, the highest ammonia emission was observed in F0T. The cumulative ammonia emission of F1T and F3T for 12 days were very similar and were about 4.7 times less than that of the F0T treatment. CONCLUSIONS: Ammonia emission in paddy field could be significantly reduced by liquid pig manure application after flooding rather than application of liquid pig manure in flooding condition. Therefore, flooding after liquid pig manure application would provide much more nitrogen for rice growth due to the reduction of ammonia emission.

돈분액비 시용이 감자 생육, 토양화학성 및 침투수질에 미치는 영향

This study was carried out to determine the effects of pig slurry on growth of potato (Solanum tuberosum L. cv. Dejima), soil chemistry properties and infiltration water quality in volcanic ash soil and non-volcanic ash soil of Jeju. Fertilization of liquid pig manure was based on nitrogen. In volcanic ash soil and non-volcanic ash soil, there was no difference in the height and diameter of stems in chemical fertilizer and liquid pig manure application treatments. Also yields of potatoes were no significantly difference in chemical fertilizer and liquid pig manure application treatments. pH in all soil was increased by application of liquid pig manure compared to the chemical fertilizer plot. Contents of exchangeable K in all soil were accumulated excessively by fertilization of pig manure 100% compared to the chemical fertilizer 100%. But there was no difference between the chemical fertilizer 50%+liquid pig manure 50% and chemical fertilizer 100%. No difference between the chemical fertilizer and liquid pig manure was observed in available phosphate, exchangeable Ca and Mg. -N concentration of infiltration water sample collected at 70cm of soil depth was lower non-fertilizer than chemical fertilizer and liquid pig manure application treatments. In volcanic ash soil, the -N concentration of infiltration water was decreased from early, except liquid manure 100%. In non volcanic ash soil, the -N concentration of infiltration water increased until October 8, but then was reduced. In all soils, -N concentration of infiltration water was higher in the liquid manure 100% than those in the chemical fertilizer 100% and chemical fertilizer 50%+liquid pig manure 50%, but there were no differences. In conclusion, the growth of potato, fertilization of soil and -N content of infiltration water were not different between chemical 50%+liquid pig manure 50% and chemical 100% plot. So, liquid pig manure could be substituted for some amount of chemical fertilizer.

An evaluation of the combined usage of separated liquid pig manure and inorganic fertiliser in nutrient programmes for winter wheat production

The effect of spring application of separated liquid pig manure (LPM) in combination with medium to high levels of inorganic nitrogen (N) to winter wheat was investigated in a field trial study at two sites in two successive growing seasons (2007–2008). The key crop parameters examined were crop N uptake (CNU), N use efficiency and grain yield. The LPM product (3.5–4.0 g/kg total N) was applied at three application rates: 15, 30 and 45 m 3/ha using a band spread application technique. The LPM was used in combination with reduced and recommended inorganic N levels; a zero N control was also included. Weather conditions in both seasons were similar with below average rainfall levels in spring followed by above average summer rainfall levels. The zero N control gave lowest CNU levels in both growing seasons (70–88 kg N/ha). Inorganic N application at the reduced and recommended N rates increased CNU levels by approximately 100 kgN/ha and 112 kgN/ha, respectively compared to the untreated control. Liquid pig manure application resulted in an additional crop uptake of 58 kgN/ha. Nitrogen use efficiencies for LPM ranged from 23 to 56% while inorganic N use efficiency levels were higher ranging from 58 to 73%. Lowest grain yield levels were measured from the zero N control (range 3.95–5.01 t/ha). The application of inorganic N increased grain yield levels by a minimum of 4.05 t/ha with LPM usage increasing grain yield levels by an additional 0.2–1.09 t/ha. This study showed that LPM could be successfully used in combination with inorganic fertilisers for the improved N nutrition of winter wheat in spring as part of an integrated nutrient programme.

Energy requirements for transport and surface application of liquid pig manure in Manitoba, Canada

The objective of this study was to conduct a thorough accounting of energy used to transport liquid pig manure from farm storage to the field and to surface-apply the manure. Energy consumption was determined using both energy data from the literature plus data from field-scale research. Energy consumption was compared between two manure application systems (the drag hose and the slurry wagon systems) and two application timing treatments (single vs. twice-annual manure application). The single annual application of liquid pig manure applied at 81.5 m 3 ha −1 and transported 1.8 km from storage to field consumed 2180 MJ ha −1 with the drag hose system and 2185 MJ ha −1 with the slurry wagon system. The twice-annual manure application regime used 2726 and 2209 MJ ha −1 for the drag hose and slurry wagon systems, respectively. When energy use was calculated on the basis of MJ per kg of available N, liquid pig manure applied once annually with the slurry wagon system provided N at 17.76 MJ kg −1 of available N, which was 33% of the energy cost of N from anhydrous ammonia and 23% of the energy cost of N from urea. Manure transport distance could be increased to 8.4 km before the energy cost per kg of available N from pig manure was equivalent to anhydrous ammonia, and up to 12.3 km before the energy cost of manure N was equivalent to urea N. Despite the high energy cost to deliver liquid pig manure from storage to field, the much lower cost per kg of available N compared to inorganic fertilizer N highlights the opportunities that exist for improving the energy efficiency of industrial agriculture by replacing inorganic fertilizers with manure.

Nitrogen and carbon isotope responses of Chinese cabbage and chrysanthemum to the application of liquid pig manure

The effects of the liquid pig manure (LM) used in organic farming on the natural abundance of 15N and 13C signatures in plant tissues have not been studied. We hypothesized that application of LM will (1) increase δ15N of plant tissues due to the high δ15N of N in LM as compared with soil N or inorganic fertilizer N, and (2) increase δ13C of plant tissues as a result of high salt concentration in LM that decreases stomatal conductance of plants. To test these hypotheses, variations in the δ15N and δ13C of Chinese cabbage (Brassica campestris L.) and chrysanthemum (Chrysanthemum morifolium Ramatuelle) with two different LMs (with δ15N of +15.6 and +18.2‰) applied at two rates (323 and 646 kg N ha-1 for cabbage and 150 and 300 kg N ha-1 for chrysanthemum), or urea (δ15N = -2.7‰) applied at the lower rate above for the respective species, in addition to the control (no N input) were investigated through a 60-day pot experiment. Application of LM significantly increased plant tissue δ15N (range +9.4 to +14.9‰) over the urea (+3.2 to +3.3‰) or control (+6.8 to 7.7‰) treatments regardless of plant species, strongly reflecting the δ15N of the N source. Plant tissue δ13C were not affected by the treatments for cabbage (range −30.8 to −30.2‰) or chrysanthemum (−27.3 to −26.8‰). However, cabbage dry matter production decreased while its δ13C increased with increasing rate of LM application or increasing soil salinity (P < 0.05), suggesting that salinity stress caused by high rate of LM application likely decreased stomatal conductance and limited growth of cabbage. Our study expanded the use of the δ15N technique in N source (organic vs. synthetic fertilizer) identification and suggested that plant tissue δ13C maybe a sensitive indicator of plant response to salinity stress caused by high LM application rates.

Effect of long-term liquid pig manure application on atrazine mineralization in a soil cultivated with maize

Soil samples were collected in plots from a field experiment in maize monoculture receiving 0, 60 and 120 m3 ha-1 liquid pig manure (LPM) for 19 years. Soils were sampled from the 0- to 20-cm layer in August and October 1997 and in June, July and September 1998. Subsurface samples were also evaluated in September 1998. Laboratory soil radiorespirometry was used to evaluate atrazine mineralization using [U-ring-14C]-atrazine mixed with commercially available product. The effect of atrazine dose (50, 100 and 500 mg atrazine kg-1 soil) was evaluated on soils sampled in August 1997. For the other sampling dates, the soils were spiked with 50 mg atrazine kg-1 soil. No LPM dose effect on atrazine mineralization was obtained in the different experiments. Increasing atrazine dose to 500 mg kg-1 decreased significantly the mineralization rate (Ri) and the maximum of atrazine mineralized (MAX), while the time needed to mineralize 50% of MAX (DT-50%) was not significantly affected. Sampling time had a significant effect on atrazine mineralization. Atrazine mineralization in the soils sampled in June 1998 showed lower Ri and MAX than in the soils sampled at the other dates. Atrazine mineralization in subsurface soils (20–60 cm) was very variable and quite high in some samples. This may be due to atrazine pre-exposure in subsoils resulting from atrazine deep movement by preferential flow.