Amounts Of Soil Nutrients Research Articles

Nitrogen release and microbial community characteristics during the decomposition of field‐incorporated corn straw in Northeast China

AbstractStraw incorporation increases the amount of nutrients in soil and greatly impacts soil nitrogen and microbial communities. In this study, 15N‐labeled corn straw was used as the material, the experiment consisted of five treament (AS: placing the straw 15 cm above the soil surface, SM: using the straw to mulch the soil surface, B15: burying the straw 15 cm below the ground surface, B30: burying the straw 30 cm below the ground surface, B45: burying the straw 45 cm below the ground surface). The changes in 15N abundance in straw were analyzed. An estimation method for nitrogen release and uptake by field‐incorporated straw was proposed, and the relationships between nitrogen release and uptake and related microbes were established. The results showed that the exchange of nitrogen between maize straw buried in soil at different depths and the environment was not significant. The corn straw exposed to the air absorbed more nitrogen from the environment in the second year of decomposition, and the larger the area exposed to the air was, the more nitrogen was absorbed from the environment. The relative abundances of Burkholderiales, Flavobacteriales, Pseudomonadales, and Sphingobacteriales were significantly positively correlated with the straw decomposition rate and nitrogen release rate. The relative abundance of Rhizobiales was significantly negatively correlated with the straw decomposition rate and nitrogen release rate. The relative abundances of Sphingobacteriales, Flavobacteriales, and Pseudomonadales were significantly negatively correlated with the straw nitrogen uptake rate.

The Effect of Soil Amendments and Precipitation on the Amount of Soil Nutrients in Different Time Periods

The Effect of Soil Amendments and Precipitation on the Amount of Soil Nutrients in Different Time Periods

Ecological assessment of the nitrogen budgets of livestock production systems in Ukraine

The nitrogen budgets was modeled on the example of 5 typical Ukrainian livestock farms of different livestock production systems. The relative anthropogenic load of different livestock systems and the efficiency of the use of nutrients in the production of crop and animal products are shown. Input flows of nitrogen (N) — in the fodder for livestock, fertilizers, biofixation, atmospheric deposition, crop residues and output flows with agricultural crop & livestock products were determined. It was established that the efficiency of nitrogen use (NUEfarm) is 21.0–69.9% on the investigated farms, i.e., such amount of soil nutrients and imported feed in nitrogen equivalent was deposited in the sold products, and the rest of N was deposited in by-products (crop residues & manure). The ratio of produced main and by-products in nitrogen equivalent was determined. In crop production, 1.06– 1.11 Mg N of grain is obtained for 1 Mg of N crop residues. In livestock, only 0.15–0.78 Mg N of the main products (milk, meat, wool) are obtained for 1 Mg of manure nitrogen production (nitrogen excretion). According to the level of output of the main products relative to by-products, the livestock systems are in the following ranked order: cattle farming — 0.15 Mg N of milk and live weight gain per 1 Mg manure nitrogen production; pig farming — 0.43 Mg N of live weight gain per 1 Mg N excreted and broiler farming — 0.78 Mg N of live weightgain, respectivel. It was established that the livestock production systems cause a significant anthropogenic load on the surrounding natural environment — intensive soil load (balance from –30.2 to –42.2 kg N/ha/year) and high rates of ammonia and greenhouse gas emissions (NH3, NOx and N2O) from manure management systems and agricultural land (16.3–1456.4 kg/ha/year). It was established that 132.4 kg of NH3, NOx and N2O are emissed for 1 Mg of live weight gain of calves; 7.6 kg of NH3, NOx and N2O per 1 Mg of produced cow’s milk; 30.3 kg of NH3, NOx and N2O per 1 Mg of live weight gain of pigs (on average); 22.2 kg of NH3, NOx and N2O per 1 Mg of live weight gain of broiler chickens; 53.7 kg of NH3, NOx and N2O per 1 Mg of produced live weight and wool of sheep.

Changes in the Vegetation, Soil Seed Bank and Soil Properties at Bait Sites in a Protected Area of the Central European Lower Montane Zone

Feeding places for shooting wild boar (so-called bait sites) are spreading in some regions and they have a growing impact on natural ecosystems. Bait sites were investigated to detect the changes in vegetation, the soil seed bank and soil nutrients. The study area is situated in the Mátra Landscape Protection Area, representing a typical oak forest in the Central European lower montane zone (in Hungary). Two types of bait sites were selected: forests and clearings. A vegetation survey, a soil seed bank experiment and a soil analysis were conducted. The degree of degradation of vegetation was similar at the various bait sites, but only the abundance of weeds was higher in the clearings. The density of weed seeds in the soil varied regardless of type, clearly showing the effects of artificial seed sources. The number of weed species was, however, significantly higher in the clearings. The degree of Jaccard-similarity between the vegetation and the seed bank was the highest in the clearings. The dominance of long-term persistent seeds did not differ among bait sites, indicating frequent disturbances at these sites. The amount of soil nutrients was significantly (more than 10 times) higher in the clearings and this, along with their greater openness, may be responsible for the higher number of weed species in their seed banks. The vegetation and the soil of the clearings proved to be more degraded, mainly due to their habitat characteristics, but the seed bank was similarly infected in the less weedy forests; thus, all bait sites may equally be the focal points of a possible invasion. It means new challenges for the management, considering that climate change and the intensive logging and hunting activities can strengthen the effects of bait sites.

Yield Variability in Oil Palm Plantations in Tropical India Is Influenced by Surface and Sub-Surface Soil Fertility and Leaf Mineral Nutrient Contents

Oil palm (Elaeis guineensis Jacq.), an industrial oilseed crop, is the most prominent oil-producing crop in the world and one of the highest dry matter producers among C3 plants. It removes large amounts of soil nutrients to support its substantial biomass and oil production. Thus, maintaining adequate levels of limiting nutrients at favorable ratios in the soil is crucial to sustain the required palm nutritional status and oil production over extended periods. We evaluated the levels and ratios of the available soil and leaf nutrients in high-yielding (HYOPP) and low-yielding (LYOPP) oil palm plantations from two locations in southern India and assessed their relations to develop effective nutrient management for sustaining fresh fruit bunch (FFB) production. The FFB yield varied from 2.00 to 31.0 t ha−1 (location 1) and 6.84 to 30.9 t ha−1 (location 2), and the FFB yields of the high- and low-yield population at each location differed significantly. Wide ranges of soil properties, available nutrients, and leaf nutrients concentrations were observed at 0–20- and 20–40-cm soil depths at both locations. The soil nutrient ratios at both sampling depths of the HYOPP were significantly different than the LYOPP at location 1. The mean leaf N (2.09%) and K (0.68%) concentrations at location 2 were significantly higher than those in location 1 (1.85% and 0.54, respectively). The mean leaf concentrations at both locations followed the order N (1.85%, 2.09%) > Ca (1.65%, 1.36%) > K (0.54%, 0.68%) > Mg (0.49%, 0.47%) > S (0.16%, 0.18) > P (0.11%, 0.12%) > B (35.8 mg kg−1, 27.5 mg kg−1). We observed positive and significant correlations between the available N and P at 0–20 cm and between the available N and K as well as Ca and S at both soil depths for HYOPPs. In LYOPPs, the available N was significantly correlated with the available P, K, Ca, and Mg at both soil depths and with the available S at 0–20 cm. The FFB yield of LYOPPs was positively and significantly correlated with the available P and S at the 0–20-cm soil depth and with the available N and P at the 20–40-cm soil depth. Except for a negative correlation (p < 0.05) with exchangeable Ca at the 20–40-cm soil depth, the FFB yield in HYOPPs had no significant correlation with the available soil nutrients at both depths. The FFB yield of LYOPPs had a positive significant (p < 0.01) correlation with the leaf P and K concentrations, while the yield of HYOPPs had a negative correlation (p < 0.01) with the leaf P. Fertilizer accounts for a large part of the on-farm cost in oil palm plantations, and an evidenced approach for fertilizer management based on nutrient contents and ratios in the soil and in the plant is useful for sustainable and profitable production of palm oil.

Новая математическая модель продуктивности подсолнечника в зависимости от площади питания растений

The article provides a brief analysis of the results of plot and field experiments to study the productivity (yield) of sunflower, depending on the area of plant nutrition, performed at VNIIMK. Based on the analysis of the experimental dependencies that determine the change in yield, the following statement is applied: yield (y) and its increase rise with an increase in the amount of growth factor (x) and are proportional to the amount of yield (A - y) that does not reach the maximum the limiting value (A), and the possible yield value (B + y), is higher than a certain minimum (initial) value (B) of the yield. The analytic formulas for the quantitative determination of yield value (у), maximum limiting yield (A), amount of nutrients in soil, a rate of action of growth factors, etc. are present for the first time. These formulas allow studying many problems of soil management in certain hydro-temperature conditions and landscape. The samples of accounts due to the new methodology which showed good correspondence between test and theme data are presented.

Evaluating the Effects of Biochar with Farmyard Manure under Optimal Mineral Fertilizing on Tomato Growth, Soil Organic C and Biochemical Quality in a Low Fertility Soil

Biochar amendments are widely recognized to improve crop productivity and soil biogeochemical quality, however, their effects on vegetable crops are less studied. This pot study investigated the effects of cotton stick, corncob and rice straw biochars alone and with farmyard manure (FYM) on tomato growth, soil physico–chemical and biological characteristics, soil organic carbon (SOC) content and amount of soil nutrients under recommended mineral fertilizer conditions in a nutrient-depleted alkaline soil. Biochars were applied at 0, 1.5 and 3% (w/w, basis) rates and FYM was added at 0 and 30 t ha−1 rates. Biochars were developed at 450 °C pyrolysis temperature and varied in total organic C, nitrogen (N), phosphorus (P) and potassium (K) contents. The results showed that biochars, their amounts and FYM significantly improved tomato growth which varied strongly among the biochar types, amounts and FYM. With FYM, the addition of 3% corncob biochar resulted in the highest total chlorophyll contents (9.55 ug g−1), shoot (76.1 cm) and root lengths (44.7 cm), and biomass production. Biochars with and without FYM significantly increased soil pH, electrical conductivity (EC) and cation exchange capacity (CEC). The soil basal respiration increased with biochar for all biochars but not consistently after FYM addition. The water-extractable organic C (WEOC) and soil organic C (SOC) contents increased significantly with biochar amount and FYM, with the highest SOC found in the soil that received 3% corncob biochar with FYM. Microbial biomass C (MBC), N (MBN) and P (MBP) were the highest in corncob biochar treated soils followed by cotton stick and rice straw biochars. The addition of 3% biochars along with FYM also showed significant positive effects on soil mineral N, P and K contents. The addition of 3% corncob biochar with and without FYM always resulted in higher soil N, P and K contents at the 3% rate. The results further revealed that the positive effects of biochars on above-ground plant responses were primarily due to the improvements in below-ground soil properties, nutrients’ availability and SOC; however, these effects varied strongly between biochar types. Our study concludes that various biochars can enhance tomato production, soil biochemical quality and SOC in nutrient poor soil under greenhouse conditions. However, we emphasize that these findings need further investigations using long-term studies before adopting biochar for sustainable vegetable production systems.

Leaf nutrients in Prosopis pallida are determined by soil chemical attributes under eutric conditions in a dryland forest

Soil pH, EC, and salinity explain the leaf nutrient concentrations of Prosopis pallida despite the high amount of soil nutrients near the trees. Dryland forests constantly face extreme abiotic conditions, and this affects plant growth and nutrition. We have determined the effects of soil chemical attributes and soil nutrients on the leaf nutrient concentrations of eight Prosopis pallida populations located along a climatic gradient in the North-Peruvian dryland forests. We analyzed the leaf chemical composition (N, P, K, Ca, Mg, Fe, Mn, Cu, and Zn), as well as soil chemical attributes [texture, pH, salinity (electrical conductivity; EC), and the sodium adsorption ratio (SAR)] and soil nutrient concentrations (the same elements as in the leaves) at 2 m from the base of each tree. The soil and leaf nutrient concentrations were not associated with the climatic gradient and were highly variable within populations. Despite the dry conditions, the soil nutrients were not a limiting resource (eutric conditions), and thus the soil chemical attributes were the main driver of the variation in leaf nutrient concentrations. Interestingly, leaf Mn was correlated with soil and leaf nutrients, as well as with soil chemical attributes, suggesting it can be used as an early indicator of plant nutrition.

Nutrient dynamics under different regimes of stocking and cattle type of temperate pastures in Hokkaido, Japan

AbstractFertilizer recommendations for day and night grazing of milking cattle on land in Hokkaido are based on previous studies of nutrient dynamics. This study confirmed the applicability of recommendations to different grazing conditions and conducted observations to extend the versatility of the fertilizer recommendation. We estimated the dynamics of fertilizer nutrients under various grazing regimes, namely with different cattle types (dairy heifers, beef breeding cows or beef heifers), stocking methods (rotational stocking or continuous stocking), seasons (throughout grass growing season or after harvest of the first crop) and times (24‐hr grazing or time restricted to 5–9 hr/day). Body weight, herbage intake and excretion were measured, and the total intake and return of nutrients to the pasture were calculated. Nutrient removal by grazing, calculated as intake minus return through excretion, increased with herbage intake. Almost all the nutrients removed under grazing throughout the growing season approached the upper or lower limits of our previously reported levels. In many cases, changes in the amounts of soil nutrients with grazing were close to the estimated amounts removed from the soil in the grass growth periods. These results show that the pasture nutrient dynamics quantified in our previous study for lactating cattle are also applicable to dairy heifers and beef cattle and to time‐restricted grazing as well as grazing after 1st cut. Regression equations were obtained to predict the fertilizer recommendations from herbage intakes for these various grazing conditions.

Evaluation of mangrove rehabilitation project at Carey Island coast, Peninsular Malaysia based on long-term geochemical changes

A project for mangrove rehabilitation purpose has been carried out at intertidal area of Carey Island, Peninsular Malaysia in early 2009. As part of the project, a detached low-crested breakwater has been constructed near the bare degraded mangrove area to reduce wave energy and storm surges forcing the site. The breakwater is also expected to trap the sediment behind its structure as well as soil nutrients needed for mangrove seedling. This study attempts to evaluate the changes of seabed elevation and geochemical in soil around the degraded mangrove area after 6 years implementation of the breakwater’s structure. Seabed elevations at degraded mangrove area (rehabilitated area) and concentration of soil nutrients at three locations (rehabilitated area, non-rehabilitated area and natural forest area) were monitored on October 2015. The seabed elevations on October 2015 are compared to the seabed elevation in January 2009 to determine the seabed level changes. In addition, the values of soil nutrients at rehabilitated area were compared to soil nutrients at non-rehabilitated area and natural mangrove forest to evaluate the geochemical condition of soil at mangrove degradation area for preparation of mangrove seedling planting. The results present that there is an increment of seabed elevations at the degraded mangrove area after 6 years construction of the breakwater (approximately 32 cm in average). The results also show a significant increase in the amount of soil nutrients on the top soil (approximately 0 to 20 cm depth) especially carbon, nitrogen and potassium at degraded mangrove area with almost similar to soil nutrients in natural mangrove forest. It demonstrate that the condition of degraded mangrove area after 6 year implementation of the breakwater is conducive for replanting the mangrove seedlings to restore the endangered mangroves at intertidal area of Carey Island, Peninsular Malaysia.

Nutrient balance under wheat-mungbean-T. Aman cropping pattern in calcareous soils of Bangladesh

Field experiments on Wheat-Mungbean-T. aman cropping pattern were conducted at Regional Pulses Research Station (RPRS), Madaripur in calcareous soils under Low Ganges River Floodplain (?EZ-12) during 2009 to 2010 to prepare nutrient balance sheet for the cropping pattern and fertilizer recommendation for study area. The treatments were T1= Control; T2 = Farmer’s practice; T3 = AEZ based recommended fertilizer dose and T4 = Soil test based fertilizer dose. The experiment was laid out in RCBD with three replications. Results revealed that the average yields of wheat, mungbean and T. aman ranged from 1517 to 3124 kg ha-1, 1320 to 1863 kg ha-1 and 2974 to 4859 kg ha-1, respectively. Grain yield of all crops increased significantly higher in soil test based (STB) fertilizer treatment (T4) over the other treatments. Among the major nutrients, the magnitude of negative balance was greater with N and K followed by Mg and Ca. The negative balance of N (-56.0 to -183 kg ha-1), K (- 71.0 to -167 kg ha-1), Ca (-7.50 to -27.1 kg ha-1), and Mg (-16.7 to -35.7 kg ha-1) was observed in all the managements might be due to added lower amount of nutrients in soil and higher removal by the crops from the soil. Positive balance of P indicated that the added amount of P is larger than the removal; P fertilization was enough to make apparent balances positive. Across various treatments, there was some amount of positive apparent S balance except absolute control plots and farmer’s practice. On the other hand, Zn and B balance in the system was neutral to slightly positive. Results revealed that, N, K, Ca, and Mg balance after two years of cropping was negative regardless of soil type and management strategies adopted. There was an improvement in organic matter in all treatments where biomasses of mungbean were incorporated. Organic matter, N, P, S, Zn and B status in soil was improved due to soil test based fertilization over the initial status. Considering the gross margin and soil fertility the soil test based (STB) fertilizer management practice is economically profitable and sustainable.Bangladesh J. Agril. Res. 42(1): 121-136, March 2017

Effects of long-term experimental warming on plant community properties and soil microbial community composition in an alpine meadow

Climate change is likely to alter the relative abundances of plant functional groups and the interactions between plants and soil microbes that maintain alpine meadow ecosystems. However, little is known about how warming-induced alterations to aboveground biomass (AGB) affect soil nutrients and microbial communities. We investigated plant community characteristics in 2002-2009 and analyzed soil properties and the soil microbial community in 2007-2009 to study the effects of warming in Qinghai Province, China. Sampling involved the use of warmed open top chambers, the monitoring of plant community characteristics, the quantification of total and available amounts of soil nutrients, and the evaluation of microbial community composition using phospholipid fatty acid (PLFA) analysis. Experimental warming initially significantly increased the number of plant functional groups and plant community AGB; however, plant community diversity and species richness decreased. Nevertheless, all these variables stabilized over time. Fungal and bacterial abundance, total nitrogen, available nitrogen and soil organic matter increased with warming, while microbial PLFAs decreased. These findings demonstrated that climate change drivers and their interactions may cause changes in soil nutrients and the abundance and content of soil microbial PLFAs. Elevated temperature has strong effects on aboveground grass biomass. Surface conditions and disturbance affect the soil microbial communities of deep soil layers.

Spatial distribution of soil‐available phosphorus and single‐point phosphorus buffering index in the Khoy region, Iran

AbstractKnowledge of the amount of nutrients in soil is required to achieve sustainable management. The objective of this study was to assess the variability of soil‐available and single‐point buffering index of phosphorus (P) in the farmlands of the Khoy region, Iran. Composite soil samples (0–30 cm) were collected at 114 locations on regular grid of 1000 m. Some soil physico‐chemical characteristics such as soil texture, soil organic matter (OM) content, soil pH, electrical conductivity (EC), calcium carbonate equivalent (CCE), available P (Pava) and single‐point P sorption index (PSI) were measured. Results showed that all variables in this study have spatial distribution in the effective range of 1500–4800 m. Moreover, experimental semivariograms of all studied variables were best‐fit by spherical and exponential models. Most importantly, kriged maps revealed that a major part of the study area contains high Pava, which is seemingly due to the frequent application of phosphate fertilizers along with poultry manure. Some soils in the western part showed low PSI index; they therefore need more P fertilizer application. In addition, due to the lower PSI value in the eastern half of the study region, applying less fertilizer at more frequent intervals seems to be more beneficial than larger single applications. Eventually, to reduce environmental risks and prevent the loss of natural resources, the method of applying P fertilizer needs to be mainly based on the created PSI distribution map.

Variations in leaf and root stoichiometry of Nitraria tangutorum along aridity gradients in the Hexi Corridor, northwest China

Nitrogen (N) and phosphorus (P) concentrations and N: P ratios between leaves and roots of Nitraria tangutorum along aridity gradients were studied. N. tangutorum was relatively limited by N in April (mean leaf N: P ratio = 11.13) and by P in August (mean leaf N: P ratio = 38.78). N and P in both leaves and roots were highly correlated across sampling sites. In April both leaf and root N and P concentrations increased along aridity gradients. Mean leaf N: P ratios changed slightly, but mean root N: P ratios increased with increasing aridity gradients. We suggest that leaf N: P ratios can indicate nutrient status at different plant growth stages, and root N: P ratios can signify if the amount of soil nutrients is insufficient.

The Evaluation of Corn and Peanut Intercropping on Efficiency of Use the Environmental Resource and Soil Fertility

Order to study the effect of density, the control weed and various proportion corn (704 Variety) and peanut (Goli Variety) intercropping an experiment was conducted in 2012 in Research station of agriculture, University of Zabol. The experiment design was factorial in randomized complete block design with three replications. Experiment factors consisted of planting proportions in 4 levels (sole crop of corn, 50% corn + 50% peanut, 100% corn + 100% peanut and sole crop of peanut), control weed in 3 levels (non-weeding, once-weeding and twice-weeding) and the space between rows in 2 level (40 and 50 cm) has been considered. The evaluated Characteristics in environmental sources are (Photosynthetic Active Radiation, Temperature and soil Moisture), the nutrients of soil include (N, K, Na, Mg, Ca, and C) and to evaluate intercropping of pure was used land equivalent ratio and economical yield. All Characteristics of study were affected by planting system.There was significant interaction between planting system, weeding and density in the absorption of light, temperature and moisture of soil. The results showed that photosynthesis active radiation absorbed by the intercropping was higher than sole crop in both plants. The results showed that changes in soil nutrient capacity of single elements (Na and K) in the treatment of mixed and monoculture peanut was more than monoculture corn and divalent elements (Ca and Mg) in mixed and monoculture corn more than mixed replacement and peanut monoculture. The highest land equivalent ratio (1.048) was accounted additive intercropping. Generally the mixed cultures with increasing density and control weed caused increase soil fertility and amount of soil nutrients after harvest. Treatment 100% Corn +100% peanut was the best treatment because using sources and increasing soil fertility and crop yield in comparison to sole crop.

Hydrology affects carbon storage potential of prairie potholes

Prairie potholes, the small, dynamic, unconnected ponds that dot central Canada as well as parts of the north central United States, can store significant amounts of soil nutrients that can be transformed to carbon dioxide and other greenhouse gases. Scientists would like to better understand how these regions could contribute to climate warming, but there are challenges, given the large heterogeneity in greenhouse gas emissions over the prairie pothole landscape.

Biomass accumulation during reed encroachment reduces efficiency of restoration of Baltic coastal grasslands

AbstractQuestionTo what extent is restoration of vegetation in coastal grasslands delayed by accumulation of nutrients after abandonment of traditional management and subsequent reed encroachment? How does nutrient flow in the plant–soil system react to reintroduction of grazing?LocationCoast of Baltic Sea, western Estonia.MethodsAbandoned, continuously managed and restored coastal meadows were selected in four different study regions and their vegetation composition sampled. Nitrogen, P, K, Na, Ca and Mg concentrations and C/N ratios were determined in both vegetation and soil. Differences between management groups were evaluated.ResultsComparison among different management groups revealed several differences in both relative and total amount of nutrients in soil and vegetation. Most soil properties of restored sites were similar to those in abandoned sites. Carbon stock in the soil profile doubled after abandonment, total N concentration in the top soil layer increased while plant available P concentration decreased. The phytomass and chemical composition of phytomass rapidly changed back to a ‘normal’ level after restoration. Species composition remained different, but species typical of coastal grasslands were present in restored sites. There was a strong site specificity in the results.ConclusionsRe‐establishment of grazing had a rapid impact on plant biomass of coastal grasslands. Species composition responded more slowly, but target species returned relatively quickly. Slow recovery of soil properties, however, means that the results of restoration may be fragile and return of tall‐growth vegetation is very probable if managent intensity declines. Long restoration periods should be planned to reach pre‐abandonment environmental conditions when using non‐destructive restoration methods.

The potential ability of swine nutrition to influence environmental factors positively12

Environmental issues are a growing concern within agriculture. Several of them can be categorized under the following headings: manure storage and handling, air quality, manure nutrient concentrations, and amounts of soil nutrients. Recently introduced, EcoCare feed (Land O'Lakes Purina Feed LLC, Shoreview, MN) is a dedicated and affordable feeding program addressing manure management, ammonia emissions, and nutrient excretion while optimizing pig performance. Components in EcoCare feed reduce manure solids and viscosity, resulting in improved physical uniformity of the manure, making it easier to agitate in manure storage pits and manipulate through manure-handling equipment. Internal research trials have indicated a reduction of 14% in solids and 22% in viscosity over a 45-d collection period; these physical changes may have positive implications for manure pit pump-out and facility sanitation. EcoCare feed also has the potential to reduce ammonia emissions. This is achieved primarily by inclusion of crystalline AA, specific Bacillus bacteria, and saponin-derived compounds. Emissions measured in a manure-pit simulation trial performed at LongView Animal Nutrition Center (Gray Summit, MO) demonstrated that pigs consuming EcoCare feed excreted manure in which ammonia volatilization was reduced by 18% over a 45-d period when compared with control pigs. Over time, EcoCare feed may result in reduced production of ammonia by up to 40% in commercial situations. Nutrient manipulation of feed can help greatly in the reduction of nutrient waste. Reducing N loss can be achieved by incorporating supplemental crystalline AA in the diet and by using specific feed additives that can reduce the volatilization of N-containing ammonia from manure pits. The excretion of P can be reduced by using phytase in the diet, thereby improving P digestibility and reducing the requirement for dietary inorganic P. These types of manipulations can be achieved without limiting swine growth performance. In fact, EcoCare feed has been shown to improve the feed conversion ratio by up to 4% over other standard feeds in field conditions.

Features of soil enzyme activities and the number of microorganisms in plantations and their relationships with soil nutrients in the Qinling Mountains, China

We studied the distribution of soil nutrients, the number of soil microorganisms, soil enzyme activities, and their relationships in pure and mixed plantations. Soil enzyme activities, the number of soil microorganisms, and soil nutrients were measured in plantations of Chinese pine (Pinustabulaeformis), larch (Larix kaempferi), sharp tooth oak (Quercus aliena var. acuteserrata), Manchurian catalpa (Catalpa fargesii), and mixed plantations in the Qinling Mountains, China. Compared with pure plantations, the conifer-broad-leaved broadleaf mixed plantations increased total N, available N, total P, available K, and organic matter in the forest soil; promoted the activities of invertase and urease by 16.7% and 53.8%; and increased the total amount of soil microorganisms by 95.9% and the number of bacteria by 104.5% (p<0.05). The correlations between soil enzymes, number of microorganisms, and soil nutrients were significant (p<0.05), and the correlations between the number of soil bacteria and basic nutrient prosperities (total N, available N, available K, and organic matter (OM)) were significant or highly significant. The correlations between the number of soil actinomycetes, and soil total N, available N, OM, and pH were also significant or highly significant. A suitable mixture of planted conifers and broad-leaved species improves the quality and amount of soil nutrients, increases the number of soil microorganisms and changes their redistribution. The change of soil enzymes and the number of soil microorganisms are indications of the change tendency of soil nutrients.

Soil properties in plantations of sessile oak ( Quercus petraea) and red oak ( Quercus rubra) in reclaimed lignite open-cast mines of the Rhineland

We studied the soil properties of 18-year-old plantations beneath the crowns of the native sessile oak ( Quercus petraea) and of the introduced red oak ( Quercus rubra) growing on reclaimed lignite open-cast mines. The soil properties of both plantations, which are growing on either highly fertile (loess deposits, silty loam) or on low fertile (mixture of loess and sand deposits, clayed sand) soil, were measured and compared with values taken from 2-year-old Quercus robur plantations. In plantations of Q. petraeawe generally found higher values of total carbon (C org) and total nitrogen (N tot) in the upper soil, although the amount of organic matter in the O-horizon did not significantly differ. Soils of Q. petraea plantations also exhibited higher values for microbial and faunal life. For example, microbial activity, the respiratory quotient ( qCO 2) and C-mineralization were about twice as high as for the Q. rubra plantations. Collembola and mites (Oribatei), both belonging to the soil mesofauna, reached higher densities in the Q. petraea plantations. When growing on highly fertile soils, the amount of soil nutrients (K +, Ca 2+, Mg 2+, and PO 4 3−P) did not differ between the two plantations. However, when oak trees grew on the less-fertile soil, the amount of soil nutrients was significantly lower beneath red oak. The amount of soil nutrients beneath red oak was even lower than beneath 2-year-old Q. robur plantations; the soil properties of which are almost at the beginning stage of succession. The results suggest that nutrient depletion beneath red oak when compared to sessile oak is caused both by increased immobilization into woody biomass, and by increased recalcitrance of organic matter.