Years Of Continuous Application Research Articles

Effects of Simulated Nitrogen Deposition on Soil Microbial Community Structure in Temperate Forest Based on PLFA Method

Soil microorganisms play a crucial role in the biogeochemical cycling of terrestrial ecosystems. However, previous studies on the effects of nitrogen deposition on microorganisms have primarily focused on nitrogen-sensitive tropical forest ecosystems. This study focused on soil in a temperate Korean pine plantation and conducted a field simulated nitrogen deposition experiment. The effects of different nitrogen application rates on the microbial community structure were analyzed using the phospholipid fatty acid (PLFA) method. The experiment included four nitrogen application rates: control (CK: 0 kg N ha−1 yr−1), low nitrogen treatment (LN: 20 kg N ha−1 yr−1), medium nitrogen treatment (MN: 40 kg N ha−1 yr−1), and high nitrogen treatment (HN: 80 kg N ha−1 yr−1). After seven years of continuous application of ammonium nitrate solution, the soil microbial community structure was determined using the PLFA method. The results showed that all nitrogen application rates significantly reduced the PLFA concentration of fungi and AM fungi (P < 0.05), while bacterial biomass significantly decreased in the high nitrogen treatment group. The biomass of Gram-positive bacteria, Gram-negative bacteria (G-), and actinomycetes also significantly decreased in the HN treatment group. Furthermore, long-term application of high nitrogen concentration (80 kg N ha−1 yr−1) significantly reduced soil microbial biomass and changed the fungal to bacterial ratio, thus affecting the soil microbial community structure. Redundancy analysis (RDA) of soil microbial and soil chemical properties found that the long-term simulated nitrogen deposition experiment affected the soil microbial community structure by changing the content of soil N, P elements, and soil pH values. In summary, long-term simulated N deposition can negatively affect soil microbial biomass and its community structure, and the main reason for this analysis is related to long-term N application leading to soil acidification and changes in the conversion of soil N and P elements.

Effect of Long-term Fertilization and Manuring on Soil Enzyme Activity in Rice-rice Cropping System in Semi-arid Southern India

Nutrient management practices have huge influence on soil biological health. The present study was conducted during kharif-2021 in the on-going AICRP on LTFE after 21 years of continuous application of fertilizers and manures to estimate the enzymatic activities i.e., urease and dehydrogenase activity at different growth stages of rice crop. In all the treatments, enzymes exhibited higher activity at flowering stage and thereafter the activity was decreased towards harvesting stage of the rice crop. Among all the treatments, FYM and 100% NPK+FYM treatments recorded highest dehydrogenase and urease activity, respectively as compared with all other treatments. Balanced fertilizer application i.e., 100% NPK also recorded significantly higher enzymatic activity compared with imbalanced fertilizer treatments i.e., 100% N and 100% NP during all the stages of crop growth period. Integrated nutrient management (100%NPK+FYM), FYM and 100% NPK are the best treatment with respect, to increasing enzymatic activity as compared with all other treatments. Grain yield of rice varied from 4078 kg ha-1 to 6569 kg ha-1during kharif-2021. Among all the treatments, maximum grain yield (6569 kg ha-1) was obtained with 100% NPK+FYM. Lower grain yield (4078 kg ha-1) was recorded in the treatment 100% N. Integrated use of inorganic fertilizer and organic manure resulted in higher growth parameters and maximum yield of rice. The combined use of organic as well as inorganic source of plant nutrients could be a sustainable option for optimizing the yield of rice in rice-rice cropping system in semi-arid southern India.

Use of Thin Cell Layer (TCL) to Obtain Somatic Embryogenesis.

The thin cell layer (TCL) culture system was initially reported in relation to the model plant Nicotiana tabacum, giving rise to 47years of continuous application and investigation on micropropagation and plant breeding of over 100 plant species or hybrids. The small sizes of the tissue sections (100μm to 1-2mm in thickness), its classification into transverse TCL (tTCL) or longitudinal TCL (lTCL) categories, and the interaction between the cultured cells and the culture medium are the main drivers of its efficacy in tens of plants for the induction of somatic embryogenesis, relative to the conventional in-vitro culture system. Furthermore, it promotes higher productivity and reduced time in the proliferation of cultures, which is key for the differentiation of cells and plant tissues. This chapter describes the main characteristics of the TCL sections, and the interaction between cells under in-vitro culture. In addition, it highlights the latest findings reporting the success of TCL in ornamental, herbaceous, woody, and recalcitrant plants. In most cases, studies on the use of TCL in combination with techniques such as bioreactors, histology, genetic transformation, and fidelity analysis, provide indisputable evidence that highlights the importance of this technique in plant biotechnology. Finally, the perspectives on TCL use are described, underlining the advantages and constraints of the technique for its continued use and future application.

Functional shifts in weed community composition following adoption of conservation agriculture

AbstractTo better understand the changes in weed communities following the adoption of conservation agriculture (CA), we investigated the functional composition of weed communities in fields implementing CA continuously from 1 to 21 years. Weed surveys were conducted in 100 winter wheat fields of 53 farmers in the Bourgogne‐Franche‐Comté region, Eastern France. Ten response traits were selected to highlight changes in the functional composition of weed communities, using weighted mean value for quantitative traits and an approach based on composition analysis for qualitative traits. Out of the 10 traits, four were impacted by the time following the adoption of CA significantly, whereas two only showed trends. Specific leaf area, leaf dry matter content, seed dispersal mode and soil seedbank longevity did not change over time following adoption of CA, whereas changes were observed for plant type, Raunkiær's life forms, Ellenberg's indicator value for light and, germination and flowering periods. Phanerophyte and geophyte life forms, summer‐germinating species and spring‐ and summer‐flowering species increased with time following adoption of CA. Shade‐tolerant species, not present in fields recently converted to CA, established later. Community‐weighted mean of seed mass and the percentage of graminoids tended to increase with time following adoption of CA. Some functional shifts in weed communities occurred quicker than others (i.e., summer‐germinating species increased after at least 10 years of continuous application of CA principles). These results can be used to inform farmers moving towards CA about expected changes.

Long-term effects of contrasting tillage systems on soil C and N pools and on main microbial groups differ by crop sequence

Determining the best conservation agriculture practices for increasing soil organic carbon (C) and hence soil quality is of paramount importance in the semi-arid Mediterranean environment, where soils are experiencing a continuous decline in organic matter. Therefore, the aim of this long-term study was to assess the combined effects of tillage system and crop sequence on soil organic C and biochemical properties of soil generally used as indicators of soil quality. After 23 years of continuous application of contrasting tillage systems (conventional tillage [CT], vs. no tillage [NT]) and crop sequences (wheat monoculture vs. wheat-faba bean rotation), soil samples were collected from topsoil (0–15 cm) and subsoil (15–30 cm) at three different times during a cropping year. Soil samples were analyzed for total and labile organic C pools, microbial biomass C (MBC) and microbial biomass N, basal respiration, and the abundance of main microbial groups by phospholipid fatty acids. Long-term NT increased total organic C (TOC) at a yearly rate of 0.17 g kg−1. This in turn stimulated microbial biomass, in particular Gram-negative bacteria. This suggests a higher soil quality in NT, as was confirmed by the increase in MBC/TOC and the decrease in stress indices. In contrast, no differences were observed with regard to fungal biomass. These findings suggest the need to reconsider the role of specific bacterial groups in organic C accumulation in soils of semiarid environments. It is interesting that the effects of long-term NT varied widely by crop sequence, whereas in CT changes in biochemical characteristics and in the main microbial groups due to crop sequence were modest. Thus, the interaction among various aspects of agronomic management modulates the effects of substrate quality on chemical and biological properties of soil.

Effect of long-term application of mineral fertilizers and FYM on microbial dynamics, yield and quality of FCV tobacco (Nicotiana tabacum) grown in vertisols

A long term manurial experiment (Permanent Manurial Trial) with the objective to study the effect of continuous application of organic manure (FYM) and inorganic fertilizers (NPK) on microbial diversity, yield and quality of Flue-cured Virginia (FCV) tobacco (Nicotiana tabacum L. ) as monocrop was carried out at CTRI Farm, Katheru, for 53 years commencing from 1956-57 to 2008-09. The results obtained before the closing of the experiment (2003- 2008) are discussed in this paper. The microbial dynamics expressed in terms of culturable microbial populations, i.e. bacteria, fungi, actinomycetes, Azotobacter and PSB were measured after 53 years of continuous application of mineral fertilizers and organic amendments to vertisols. The population of bacteria, actinomycetes, Azotobacter and PSB were maximum in plots treated with mineral fertilizers and FYM while fungal population was maximum in mineral fertilizers treated plots. The population of bacteria, actinomycetes, Azotobacter and PSB increased in the treatments with the addition of P and K fertilizers alone or in combination. The fungal population decreased with the addition of NPK along with the FYM. Bacillus, Pseudomonas species of bacteria and Trichoderma, Aspergillus and Rhizopus species of fungi, Streptomyces species of actinomycetes were the main dominating culturable microorganisms in all the treatments. The FYM amended plots sustained crop productivity and microbial populations at higher levels than rest of the mineral fertilizer treatments. The average cured leaf yields indicated that only farm yard manure and inorganic nitrogen application has exerted pressure in increasing the cured leaf yields by 24. 52% and 26. 97% respectively in VT-1158 variety of tobacco in vertisols. The nitrogenous fertilizers alone had the most deleterious effect on crop productivity and the biological soil environment. The results of the present study support the concept of balanced fertilization and integrated nutrient management practices for improving the soil quality and sustained crop productivity.

Effects of mulching measures on soil moisture and N leaching potential in a spring maize planting system in the southern Loess Plateau

A field experiment was conducted in the southern gully region of the Loess Plateau to study the effects of mulching measures on spring maize yield and nitrate accumulation in dryland areas under traditional tillage conditions. The study was performed to provide a scientific basis for spring maize planting and environmental protection in this area. The four treatments were non–mulching (CK), plastic film–mulching during the growth period (PM1), plastic film–mulching during the fallow period (PM2), and straw–mulching (JM). After 13 years of continuous application, the yield of spring maize, the nitrogen uptake by plants, and the nitrate nitrogen content at the harvest stage were measured. The results revealed that soil moisture content and water storage capacity of the three soil–mulching treatments were all higher than those of the non–mulching treatment. Soil water storage at a depth of 0–300 cm in the JM, PM1 and PM2 treatments was increased by 11.8%, 10.6% and 8.8%, respectively, compared with the CK treatment. Compared with the CK treatment, the mulching treatments significantly increased the aboveground biomass and grain yield of spring maize. The yield enhancement effect of the PM1 treatment was the most significant, with a yield of 1.1 Mg ha-1 and an increase of 26.72%. In addition to the JM treatment, the accumulation of soil nitrate at a depth of 0–300 cm in the PM1 and PM2 treatments was less than that of the CK treatment, but the largest increase in soil nitrate (80.20% in the JM treatment) was observed at a depth of 0–100 cm. The results suggest that in the rainfed agriculture in the southern Loess Plateau, mulching cultivation can effectively increase the soil moisture content and water storage capacity. PM1, and PM2 treatments could significantly reduce the content and accumulation of nitrate nitrogen in the deeper soil profile, and the three mulching measures could slow down the deep accumulation of soil nitrate nitrogen to a certain extent.

Effect of different mulching measures on nitrate nitrogen leaching in spring maize planting system in south of Loess Plateau

Field experiment was conducted in the southern gully region of the Loess Plateau to study the effects of different mulching measures on spring maize yield and nitrate leaching in dryland under the traditional tillage conditions, so as to provide a scientific basis for spring maize planting and environmental protection in this area. The four treatments included non-mulching (CK), plastic film-mulching (PM1), plastic film-mulching in fallow (PM2) and straw-mulching (JM). After 13 years of continuous application, the yield of spring maize, the nitrogen uptake by plants and the nitrate nitrogen content at the harvest stage were measured. The results showed that the soil moisture content and water storage capacity of three kinds of soil mulching treatments were all higher than those of non-mulching ones. Soil water storage in the range of 0 ∼ 300 cm of JM, PM1 and PM2 increased by 11.8%, 10.6% and 8.8% respectively compared with CK. Compared with CK, the mulching treatments significantly increased the aboveground biomass and grain yield of spring maize. The yield enhancement effect of PM1 was the most significant, with a yield of 11,314.42 kg / ha and an increase of 26.72%. In addition to the JM treatment, the accumulation of soil nitrate nitrogen in the range of 0 ∼ 300 cm of PM1 and PM2 was less than that of CK, but the increase of nitrate nitrogen of 80.20% of JM treatment was in the range of 0 ∼100 cm. Therefore, in the rain-fed agriculture in the south of Loess Plateau, mulching cultivation can effectively increase the soil moisture content and water storage, improve crop growth. The yield enhancement effect of plastic mulching-film was the best. PM1, PM2 could significantly reduce the content and accumulation of nitrate nitrogen in soil profile, and the three mulching measures could slow the deep leaching of soil nitrate nitrogen to a certain extent.

Impact of management practices on soil microbial properties under wheat-cluster bean cropping system

A study of organic, integrated and inorganic plant nutrient management systems was conducted to determine the effect of management practices on soil microbiological properties after 10 years of continuous application. The rate of C mineralization and potentially mineralizable nitrogen were 6.8 and 41.5 mg/kg soil, respectively. Arginine ammonification and nitrification activities were 0.88 µg NH4+- N/g soil/h and 56.0 µg NO3--N/g/day, respectively. Microbial biomass C, N and P were 320, 40 and 12 mg/kg soil, respectively. Alkaline phosphatase, urease and cellulase activities were highest with application of VC@15t /ha.

Effect of moisture content on biophysical characteristics of chickpea cultivars

A study of organic, integrated and inorganic plant nutrient management systems was conducted to determine the effect of management practices on soil microbiological properties after 10 years of continuous application. The rate of C mineralization and potentially mineralizable nitrogen were 6.8 and 41.5 mg/kg soil, respectively. Arginine ammonification and nitrification activities were 0.88 µg NH4+- N/g soil/h and 56.0 µg NO3--N/g/day, respectively. Microbial biomass C, N and P were 320, 40 and 12 mg/kg soil, respectively. Alkaline phosphatase, urease and cellulase activities were highest with application of VC@15t /ha.

Effects of long-term fertilization on available P, P composition and phosphatase activities in soil from the Huang-Huai-Hai Plain of China

Combining organic materials with chemical fertilizers is gradually becoming the primary fertilization strategy in China for increasing soil phosphorus (P) concentration; however, the relationships between soil available P, P composition and phosphatase activities in treatments with long-term crop straw or animal manure combined with chemical NPK fertilizers are not fully understood. In this study, a field fertilization experiment was conducted in a light sandy loam soil from the Huang-Huai-Hai Plain of China to determine the variation in soil available P, P composition and phosphatase activities with 23 years of continuous application of maize straw or cattle manure in combination with chemical fertilizers at the depth of 0–20cm, with special attention paid to their relationships. The experiment was arranged in a randomized block design with three replications for each treatment, including the unfertilized control (CK), chemical nitrogen (N) with phosphorus (P) and potassium (K) (NPK), NPK plus maize straw (NPKS), and NPK plus cattle manure (NPKM). Results indicated that all fertilization treatments significantly increased soil P concentration and crop yields. Among the fertilization treatments, NPKM treatment showed the significantly highest total P and available P concentrations, while no significant difference in either wheat or maize yield between NPK, NPKS and NPKM treatments was found. Compared to the application of chemical NPK fertilizers alone, the NPKS treatment significantly increased soil organic P, pyrophosphate and orthophosphate concentrations, as well as soil phosphatase activities. The increase in orthophosphate concentration under the NPKS treatment may be associated with the hydrolysis of organic P and pyrophosphate catalyzed by acid phosphomonoesterase (AcP), phosphodiesterase (PD) and inorganic pyrophosphatase (IPP), which was conducive to keeping soil available P concentration under NPKS treatment at an appropriate level that could not only satisfy crop P demand but also have no negative impacts on the environment. However, the increase of orthophosphate and available P concentrations under NPKM treatment may be primarily related to the manure P inputs, and although NPKM treatment significantly increased soil inorganic P concentration in comparison to other fertilization treatments, it also increased the risk of P leaching. Overall, from the perspective of P nutrient management, our results suggest that NPKS treatment might be an effective long-term fertilization practice in the light sandy loam soil of Huang-Huai-Hai Plain of China.

N2O emissions in a long-term soil fertility experiment under maize–wheat cropping system in Northern India

The agriculture sector is a major contributor towards global N2O (nitrous oxide) emissions. Amongst various factors controlling N2O emissions from cultivated fields, application of fertilizers and manures is the key factor. The effect of 42years of continuous application of inorganic fertilizers and farmyard manure (FYM) on N2O emissions in loamy sand soil was studied via closed chambers and gas chromatography. Daily N2O fluxes from five treatments: 100% NPK (T1), 150% NPK (T2), 100% N (T3), 100% NPK+FYM (T4) and Control (T5), of an onging experiment under maize-wheat cropping system on Typic Ustochrept in Northern India, were measured during maize and wheat crop seasons. The average N2O fluxes in T1, T2, T3, T4 and T5 treatments during maize crop season were 56.2, 60.8, 58.5, 59.2 and 24.6 N2O-Ngha−1day−1, respectively and in the wheat crop season 17.1, 19.7, 17.2, 19.4 and 11.5 N2O-Ngha−1day−1, respectively. Total N2O emissions in long-term fertilizer or manure treatments were approximately 100 and 50% higher than control in the maize and wheat crop seasons, respectively. Various long-term treatments had significant effect on status of various soils C and N forms, which in-turn influenced N2O emissions. Regression analysis revealed that water-input either from rainfall or irrigation controlled nearly 50% of the seasonal variations in N2O fluxes in the control treatment and about 20% variations in fertilizer and manure treatments. This suggested that in addition to irrigation or rainfall, fertilizer application also played an important role in N2O emissions. Although carbon-equivalent emissions were higher from balanced fertilization or FYM application treatments, yield-scaled global warming potentials (GWP) were lower due to higher maize and wheat grain yields in these treatments. Long-term maize-wheat cropping without any nutrient application or imbalanced fertilization resulted in higher yield-scaled GWP. The findings suggested that to achieve food security and curtail N2O emissions, balanced fertilization or integrated nutrient management may be adopted.

Evaluation of phosphorus availability in a lateritic gravelly, coconut grown and long term phosphate fertilizer applied soil in Sri Lanka with an indicator plant

The residual phosphorus availability and response of Ginger (Zinigiber officinale) to residual available phosphorus in (lateritic gravelly) Red Yellow Podzolic soil (RYP - Rhodustults) of Andigama soil series from Rathmalagara estate, Madampe was evaluated after 10 years of continuous application of 03 sources of phosphates to young coconut palms. A pot experiment was established using Andigama soil series which was collected from field experimental site where coconut palms were treated with 03 levels of phosphate with 03 different phosphate sources i.e., Eppawela Rock Phosphate (ERP, 30 % P2O5), Imported Rock Phosphate (1RP, 27.5% P205) and Triple Super Phosphate (TSP, 46 % P205) from the seedling stage up to the age of 10 years. The initial rates of phosphate applications were P205 equivalent of 50, 100 and 200 g palnrf'year'1 respectively which were annually increased by 5, 10 and 20 g respectively. Ginger was used as an indicator plant as the growth parameters, yield and the total P content in the ginger can be taken as an indication of the response to different treatments. Ginger rhizomes were planted in pots filled with 5 kg of phosphate treated soil and all the plants were treated with a basal dose of nitrogen (N) and potassium (K.) at every 1 V2 month intervals for 6 months. Number of tillers per bush, height of the plants and number of leaves in bush in each pot were recorded. Six months after planting, ginger plants were uprooted and fresh and dry weight of shoots of the plants, roots and rhizomes were recorded. All the plant parts were analysed for total P. Soil samples were collected before planting the ginger and analyzed for available P by 2.5 % acetic acid method, Olsen’s bicarbonate and Bray and Kurtz 1 method. The overall result showed that the extractable P in soil treated with all 03 levels of ERP, IRP and TSP by 2.5 % HAc-P, Olsen - P and Bray - P values were above the sufficiency soil P values of 7.8 mg kg-1, 8.5 mg kg-1 and 5.8 mg kg-1 respectively. The highest level of TSP, IRP and ERP treatments were significantly effective in increasing the dry weight of rhizomes and the shoots of ginger. It indicated that residual phosphorus availability of TSP, IRP and ERP was high and its effectiveness on response to ginger was more or less similar. This might be due to low dissolution of ERP and fixation of TSP in lateritic gravel soil. According to the findings of this experiment, P fertilizers can be taken out from the coconut fertilizer recommendation for a period of time by monitoring the effectiveness of the residual P status in soil and coconut leaf. Findings of this experiment can be included into site specific fertilizer recommendation programmes of the other perennial crops. By monitoring the availability of P in soil, intercrops can be grown in coconut plantations without application of P fertilizers. COCOS Vol. 20: 59-70 (2013)

Effect of continuous application of inorganic nitrogen fertilizer on selenium concentration in vegetables grown in the Taihu Lake region of China

Vegetables provide an important source of selenium (Se) for many regions of China. Excess nitrogen (N) fertilizers are commonly used for vegetable production. In this regard, the effect of inorganic N-fertilizer application on the Se content in soils and plants was evaluated in vegetables produced in a polytunnel greenhouse vegetable system. Vegetables were continuously cultivated for 6 years in a microplot field experiment and treated annually with conventional N fertilizer (870 kg ha−1 inorganic fertilizer) and 0 kg N ha−1 as control treatment in polytunnel greenhouse vegetable system in the Taihu Lake region of China. Both treatments included 234 kg ha−1 N provided by manure. After each harvest, soil and vegetable samples were collected, and analyzed for soil NO3-N, Olsen-P, Se, phosphate extractable S and Se and vegetable Se. Six years of continuous application of inorganic N-fertilizer resulted in a significant accumulation of NO3-N, Olsen-P and extractable S in the soil over the course of the experiment. Soil NO3-N concentration accumulated up to 600 mg kg−1 with application of inorganic N-fertilizer, while soil phosphate extractable Se and vegetables Se concentration were significantly lower than that those grown in control treatments. The negative effect of continuous application of inorganic N-fertilizer on vegetable Se concentration may be a consequent of excessive accumulated soil NO3-N. When NO3-N concentration was greater than 300 mg kg−1, vegetable Se concentration was negatively correlated with soil NO3-N. The negative effect of continuous application of inorganic N-fertilizer on vegetable Se concentrations was likely the result of soil nitrate’s competitive or antagonistic effect on Se uptake by vegetables grown in an intensive polytunnel vegetable cultivation system.

Weed seedbank size and composition in a long‐term tillage and crop sequence experiment

SummaryKnowledge of the effects of agricultural practices on weed seedbank dynamics is essential for predicting future problems in weed management. This article reports data relative to weed seedbank structure after 18 years of continuous application of conventional tillage (CT, based on mouldboard ploughing) or no tillage (NT) within three crop sequences (continuous wheat, WW; wheat–faba bean, WF; and wheat–berseem clover, WB). Tillage system did not affect the size of the total weed seedbank, but altered both its composition and the distribution of seeds within the soil profile. In particular, the adoption of CT favoured some species (mainly Polygonum aviculare), whereas the continuous use of NT favoured other species (Papaver rhoeas, Phalaris spp. and Lactuca serriola). The effects of tillage system on weed seedbank size and composition were less pronounced in the WB cropping system than in either the WW or WF. Compared with WF and WB, WW resulted in an increase in total weed seedbank density (about 16 000 seedlings m−2 in WW, compared with 10 000 and 6000 seedlings m−2 in WF and WB, respectively) and a reduction in weed diversity, with a strong increase in some species (e.g. Polygonum aviculare). Our results for the effect of NT application on weed seedbank size and composition suggest that farmers should only apply such a conservative technique within an appropriate crop sequence.

Effect of organic fertilization on nutrient concentration and accumulation in nectarine (Prunus persica var. nucipersica) trees: The effect of rate of application

The aim of the present investigation was to evaluate the effects of annual application of three rates of compost on nutrient concentration and accumulation in tree organs, after 11 years of continuous application of a municipal solid waste (MSW) compost in a commercial nectarine orchard. Trees were subjected, since their plantation (2001), to the following MSW compost rate: 0, 5 and 10tdwha−1yr−1, split in May (60%) and September (40%). In 2011/2012 biomass of pruned wood, thinned fruits, fruit pulp and stones at harvest, and abscised leaves were weighted and analyzed for macro (N, P, K, Ca, Mg) and micro (Fe, Mn, Cu, and Zn) nutrients concentration. In addition, leaves and fruit pulp at harvest were analyzed for heavy metal (Cd, Cr, Hg and Pb) concentration. Plant part biomass (with the exception of thinned fruits) was linearly related to compost application rate. The highest rate of compost increased N and decreased Ca and Mg concentration in leaves sampled in summer, whereas no differences among treatments were observed for the other nutrients. At the end of the season leaf N, K and Zn were remobilized to storage plant part, while P, Ca, Mg, Fe and Mn reached the highest values in abscised leaves. Nitrogen, K, Mg, Cu, Mn and Zn accumulation in the plant part analyzed increased as a consequence of the application of compost at 10tha−1 when compared with compost at 5tha−1 and control. Phosphorous accumulation was increased by compost at the highest rate compared with control; no differences were observed for Ca and Fe accumulation. Nitrogen and P were mainly accumulated in fruit, abscised leaves and pruned wood; K was allocated mainly into fruits, while Ca and Mg were found highest in abscised leaves. Concentration of heavy metals in leaves and fruits were not affected by treatments.

EFFECT OF TILLAGE AND RESIDUE MANAGEMENT ON PRODUCTIVITY OF SOYBEAN AND PHYSICO-CHEMICAL PROPERTIES OF SOIL IN SOYBEAN-WHEAT CROPPING SYSTEM

A microplot experiment was conducted in soybean–wheat cropping system at New Delhi during 2010-11 and 2011-12 to study the effect of continuous or cyclic tillage, viz., conventional tillage (CT) and zero-tillage (ZT) and residue management of either soybean (SR) and/or wheat (WR) on yield performance and soil physico-chemical properties. The experiment was laid out in randomized block design with two replications in microplots of size 4×1.4 m. Plant height of soybean was influenced due to tillage and residue management at different growth stages. All yield attributes of soybean were showed variation due to treatments. The harmful effects of ZT on yield attributes could be overcome with residue application on soil surface. The results indicated that tillage and residue management to the immediate crop of soybean was more important for increasing grain yield (26%) and stover production (32%) of soybean and the residual effect of residue to previous soybean was relatively small. The change in organic C was relatively small even with regular addition of crop residues. There was no change in available nutrients (N, P and K) due to tillage and residue management treatments. The variation in soil physical properties was also small and a significant improvement may be expected over several years of continuous application of crop residue and ZT.

Soil carbon fluxes and balances and soil properties of organically amended no-till corn production systems

The addition of organic amendments is essential for sustainable soil fertility management and crop production, but can also increase greenhouse gas (GHG) emissions. Thus, understanding the impacts of organic soil amendments on gaseous emissions is pertinent to minimizing agricultural impacts on the net emissions of GHGs. A long-term field experiment was conducted to assess the impacts of continuous application of organic amendments (i.e. compost and farmyard manure) and cover crop [mixture of rye (Secale cereal), red fescue (Festuca rubra), and blue grass (Poa pratensis L.)] on selected soil properties, apparent carbon (C) budget (calculated from the difference of sum of all sources of C inputs and outputs), gaseous flux (i.e. carbon dioxide, CO2, and methane, CH4), and relationship with weather parameters under no-till (NT) corn (Zea mays L.) cultivation in an Alfisol of central Ohio, USA. Soil properties and gaseous fluxes were measured continuously for 2years. Ten years of continuous application of soil amendments increased soil pH and electrical conductivity, enhanced soil C pool, and decreased bulk density especially in 0–5cm depth than that with cover crop and control plots. Two years average, cattle manure, compost, fallow, and cover crop emitted 14.1, 10.2, 7.5, and 7.2Mg CO2–C ha−1yr−1, respectively. Methane emission was 10.7kg CH4–Cha−1yr−1 from cattle manure and 4.0kg CH4–Cha−1yr−1 from compost. However, fallow consumed 3.3 and cover crop 5.0kg CH4–Cha−1yr−1. These data suggest that long-term application of compost in NT corn decreased emissions of CO2 by 38% and of CH4 by 167% compared to application of manuring. In general, soil temperature, air temperature, and precipitation were positively correlated with CO2 emissions. Estimation of C budget indicated that amended soil under NT is a C-sink while a non-amended system is a C-source. The application of composted soil amendments in NT corn enhances soil quality and reduces net GHG emissions.

Papermill biosolids and alkaline residuals affect crop yield and soil properties over nine years of continuous application

Gagnon, B. and Ziadi, N. 2012. Papermill biosolids and alkaline residuals affect crop yield and soil properties over nine years of continuous application. Can. J. Soil Sci. 92: 917-930. Residues from paper and wood mills are a valuable source of nutrients for field crops, but little is known about the effectiveness of repeated applications over many years. A study was initiated at Yamachiche, QC, to assess the effect of continuous applications over 9 yr of combined papermill biosolids (PB), applied alone or with several liming by-products, on grain yield, plant nutrient accumulation, and soil fertility in a loamy soil cropped to grain corn, dry bean, and soybean. The PB treatments (0, 30, and 60 Mg wet ha-1) and liming by-products [calcitic lime (CL), lime mud (LM), wood ash (WA)], and two magnesium residuals, each at 3 Mg wet ha-1 along with 30 Mg PB ha-1) were surface applied annually at post-seeding. In the last 6 yr, the two treatments receiving magnesium residuals were replaced with 90 Mg wet PB ha-1...

Papermill biosolids and alkaline residuals affect crop yield and soil properties over nine years of continuous application

Gagnon, B. and Ziadi, N. 2012. Papermill biosolids and alkaline residuals affect crop yield and soil properties over nine years of continuous application. Can. J. Soil Sci. 92: 917-930. Residues from paper and wood mills are a valuable source of nutrients for field crops, but little is known about the effectiveness of repeated applications over many years. A study was initiated at Yamachiche, QC, to assess the effect of continuous applications over 9 yr of combined papermill biosolids (PB), applied alone or with several liming by-products, on grain yield, plant nutrient accumulation, and soil fertility in a loamy soil cropped to grain corn, dry bean, and soybean. The PB treatments (0, 30, and 60 Mg wet ha−1) and liming by-products [calcitic lime (CL), lime mud (LM), wood ash (WA)], and two magnesium residuals, each at 3 Mg wet ha−1 along with 30 Mg PB ha−1) were surface applied annually at post-seeding. In the last 6 yr, the two treatments receiving magnesium residuals were replaced with 90 Mg wet PB ha−1 and mineral N fertilizer (MIN), respectively. Repeated annual applications of LM followed by CL increased soil pH the most (up to 1.4 unit). Crop yields were not significantly affected by treatments in the first 3 yr but subsequent applications of PB at 90 Mg ha−1 increased yields in grain corn (+1.9 Mg ha−1) and dry bean (+0.77 Mg ha−1) relative to the control, while PB with WA increased yield in soybean (+0.85 Mg ha−1). The PB at 30 Mg wet ha−1 with supplemental N (average of 45 kg N ha−1), or at 60 Mg wet ha−1 applied alone, achieved yields comparable with MIN treatment under corn. The PB applications increased soil organic matter and all major soil nutrients except K and Mg. The results of this study indicate that PB and alkaline residuals can be effectively applied to agricultural soils over many years although PB exceeding 60 Mg wet ha−1 yr−1 induce significant nitrate leaching.