Non Treatment Research Articles

Effect of outdoor structural enrichments on the performance, use of range area, and behavior of organic meat chickens

Chickens provided with outdoor access often do not fully use the range area. Natural cover, such as trees, can provide shelter and increase range use, but may not be practical for use in all free-range operations. A study was conducted to determine whether constructed enrichments that simulate natural structures increase range use and impact behavior of meat chickens. Slow-growing Delaware chickens were raised in floor pens (17 birds/pen) in a naturally ventilated house, with a pophole in each pen that allowed daily access to a vegetation-covered outdoor area. Feed and water were provided inside and outside. Birds were randomly assigned to one of 2 treatments: no range enrichment (control; NON) or range enrichment (ENR), which had roosts made of plastic pipe or screened shelters placed 7.6m and 22.9m from the house and overhead shade panels at 15.2m. There were 4 replications. The numbers of birds inside and in the 4 quadrants of the range were counted in 7-min intervals 3 times daily (0900h, 1300h, and 1600h) for 3 consecutive d when the birds were 7 and 10 wk of age; the numbers of birds performing various behaviors also were counted. On average, only 12.9% of birds used the range at any given time. The behavior of the birds was strongly affected by location (inside vs. outside), with birds mainly foraging and walking while outside and feeding, standing, and sitting while inside. Time of d impacted the number of birds that ranged (P ≤ 0.0001), with fewest birds outside during mid-day. Overall, birds using the range were most often (71%) observed in the quadrant nearest the house (zero to 7.6m). However, in the ENR treatment, more birds (13%; P ≤ 0.0001) were observed in the farthest 2 quadrants (15.2 to 30.5m from the house) than in the NON treatment (6%). This indicates that adding constructed enrichments to the range encouraged meat chickens to use it more fully.

Short Oxygenated Warm Perfusion With Prostaglandin E1 Administration Before Cold Preservation as a Novel Resuscitation Method for Liver Grafts From Donors After Cardiac Death in a Rat In Vivo Model.

We previously demonstrated that short oxygenated warm perfusion (SOWP) prevented warm ischemia-reperfusion injury in rat livers from donors after cardiac death (DCDs) in an ex vivo model. In the present study, we aimed to examine the in vivo effects of SOWP and SOWP with prostaglandin E1 (PGE1) in DCD rat liver transplants. We performed liver transplantation after 6-hour cold preservation using grafts retrieved from DCD rats, divided into nontreatment (NT), SOWP, and SOWP with PGE1 (SOWP + PG) treatment groups. The SOWP grafts were perfused with oxygenated buffer at 37°C for 30 minutes before cold preservation. Prostaglandin E1 was added to the SOWP + PG group perfusate. Eleven liver transplants from each group were performed to evaluate graft function and survival; 5 rats were used for data collection after 1-hour reperfusion, and 6 rats were used for the survival study. As a positive control, the same experiment was performed in a heart-beating donor group. In both the SOWP and SOWP + PG groups, serum liver enzymes, intercellular adhesion molecule 1 levels, and cellular damage were significantly decreased compared with the NT group. In the SOWP + PG group, bile production and energy status were significantly improved compared with the NT group. The 4-week survival was 0% (0/6), 67% (4/6), 83% (5/6), and 100% (6/6) in the NT, SOWP, SOWP + PG, and heart-beating donor group, respectively. Short oxygenated warm perfusion before cold preservation and the addition of PGE1 to SOWP were thus beneficial in an in vivo rat model.

Effect of split application of nitrogen on nitrous oxide emissions from plastic mulching maize in the semiarid Loess Plateau

Applying nitrogen (N) using split application to improve temporal synchronicity between crop-N demand and soil-N availability is a key strategy for improving nitrogen use efficiency (NUE). Its effect on nitrous oxide (N2O) emissions has not been well evaluated, especially from plastic mulching maize (Zea mays L.) in semiarid farmland. We conducted a two-year experiment to investigate the effect of split fertilizer N application on N2O emissions. Three approaches each applying a total of 225kgNha−1 were tested either as a single application at sowing (N1), N applied with two splits at a ratio of 4:6 (N2), and N applied with three splits at a ratio of 4:3:3 (N3), a no-N application treatment was also included as a control (N0). Compared with the single application, split application of N significantly increased the grain yields by 4.7–9.1%. The cumulative N2O emissions significantly increased by 18.1% under the three splits application in the 2014–2015 season compared with the single application but not in the growing season of 2015, which followed the same pattern with yield-scaled N2O emissions. Fertilizer application combined with precipitation was the main driving factor for N2O emissions. Therefore, the higher frequency (three times) of fertilizer application had a high risk for increasing N2O emissions due to the relatively strong and frequent precipitation in maize mid and late growth period in this region; applying N with two splits is more suitable for this region which could produce higher grain yields, and lower risk of N2O emissions.

Long term application of dairy cattle manure and pig slurry to winter cereals improves soil quality

Organic fertilizers (manures and slurries) applied repeatedly over many cropping seasons favourably influence nutrient recycling, maintenance of soil organic matter (SOM), and improve soil quality parameters such as soil aggregation and porosity. These aspects are particularly relevant in Mediterranean environments characterized by low SOM. This study was set up in a subhumid Mediterranean area where two different trials, devoted to winter cereals, were fertilized with dairy cattle manure (DCM) or pig slurry (PS) for a period of 12 years. One objective of this research was to evaluate the impacts of these fertilization practices on aggregate stability and SOM fractions, when compared with a mineral N fertilizer and a control (no-N) treatment. Porosity and pore shape were also studied in PS plots. The use of DCM significantly increased water stable aggregates by up to 16.4–18.0 %. Slurry addition did not affect aggregation but it increased the area occupied by pores >65 µm. Soil organic carbon (SOC) and light organic fraction (0.05–0.2 mm) increased with DCM incorporation but in PS treatments the SOC increment was non-significant. Data from DCM and PS together showed a positive and significant linear relationship between SOC (p < 0.05, R2 = 0.60), SOC light fraction (p < 0.01, R2 = 0.75) and SOC light fraction at 0.05–0.2 mm size (p < 0.01, R2 = 0.83), with water-stable aggregate. The use of animal residues (DCM or PS), applied according to an N criterion, increased available phosphorus and potassium soil content while improving yields. The enrichment of soil nutrients with DCM and PS use requires further research in order to avoid potential environmental impacts.

Effects of Fibroin Treatments on Physical and Biological Properties of Chitosan/Hydroxyapatite/Fibroin Bone's Scaffold

The development of bio-mimetic scaffold for tissue engineering proposed a novel method to tissue or bone repairing. The biological and physical properties of the scaffold have been recognizing such as biocompatibility, porosity, pore size, and biodegradability. In this work, Chitosan, Hydroxyapatite (HA), and Fibroin were used for bone's scaffold fabrication by freeze drying technique. Those materials are known as biodegradable materials that serve different properties in bone's scaffold. In common fabrication process, the fibroin treatment is requiring for increasing the stiffness of the fibers. Recently, the fibroin treatment is process before the scaffold fabrication. However, the treatment could process after the scaffold fabrication complete. Thus, we compared the biological and physical of the scaffolds between three conditions of fibroin treatment that consist of 1) Non-treatment (NON), 2) Pre-treatment (PRE), and 3) Post-treatment (POST). From the result, both of biological and physical properties, the PRE porous scaffold is the appropriated condition for this research. Finally, we are looking forward to compare the growth of osteoblast cells on the scaffold with different fibroin treatment and aim to implant those scaffolds for bone repairing in the very near future.

Yield response to N fertilizer and optimum N rate of winter oilseed rape under different soil indigenous N supplies

Assessing the optimum N fertilizer rate is a crucial step in nitrogen (N) management of winter oilseed rape (Brassica napus L.). We conducted 1457 site-year experiments with four N application rates, no-N (i.e., no N application), LN (i.e., half the N rate of the MN treatment), MN (i.e., current recommended N rate from local technicians), and HN (i.e., 1.5 times the N rate of the MN treatment) at the regional scale in China, aiming to evaluate the economic optimum N rate (EONR) for winter oilseed rape under different levels of soil indigenous N supply (INS). We used yield under no-N treatment to represent INS. Four INS levels (i.e., L1, L2, L3, and L4) were graded based on the relationship between the yield under no-N treatment and the relative yield (i.e., yield of no-N treatment divided by the yield of the MN treatment). The results indicated that the rapeseed yield was higher under the MN treatment than under the LN and HN treatments across different INS levels, with an average of 2267–3185kgha−1. The values of EONR were determined based on the relationship between rapeseed yield and N application rates across sites, with an average of 200, 182, 173, and 162kg N ha−1 in the levels of L1, L2, L3, L4, respectively. Currently, nearly 45% of the sites apply suitable rate of N fertilizer (i.e., nearly 180kg N ha−1) in the Yangtze River Basin. However, current N rates were insufficient (Δ N rate, i.e., N difference between the EONR and MN, higher than 10kg N ha−1) in 37% and 32% of the experiments for L1 and L2 INS levels, respectively, and excessive (Δ N rate ≤ −10kg N ha−1) in 30% and 36% of the experiments for L3 and L4 INS levels, respectively. The EONR optimized the current N rate with a yield-response model, which could increase rapeseed yield with efficient N fertilizers input under different INS levels. Our study provides data to support regional N fertilizer management systems for winter oilseed rape, especially in those countries that also plant multiple cropping systems and/or plant small-scale sites across the world.

On-farm trials of optimal fertilizer recommendations for the maintenance of high seed yields in winter oilseed rape (Brassica napus L.) production

Mineral fertilizer plays an important role in the maintenance of high rapeseed yields during oilseed rape (Brassica napus L.) production. On-farm experiments at 60 sites throughout the Yangtze River Basin in China were conducted for 2 years to evaluate the effects of the recommended fertilization rates (180 kg N ha−1, 90 kg P2O5 ha−1, and 120 kg K2O ha−1) on the rapeseed yield, and three indices of soil nutrient supply were adopted to estimate the yield responses to fertilizer recommendation. The results showed that the average contributions of nitrogen (N), phosphorus (P) and potassium (K) fertilizer to seed yield were 40.4, 23.1 and 11.5%, respectively. Compared with the farmers’ fertilization practices (FFP), the recommended fertilization significantly enhanced the seed yield by 29.1% on average. The relationships between plant-available soil nutrient supply, seed yields of the nutrient omission treatments and the yield responses to fertilization were significant, rather than the results of soil testing. With plant-available soil nutrient supplies and seed yields increasing, the yield responses and fertilizer use efficiencies decreased. When the seed yields of no-N and no-P treatments were less than 2000 kg ha−1 and 1500 kg ha−1, the recommended fertilizer rate was beneficial for achieving high seed yield and high efficiency. As defined in our study, the recommended fertilization rates could be used as the regional mean optimal rates (RMOR) of fertilization for winter oilseed rape in the Yangtze River Basin. Partial adjustments according to crop nutrient uptakes and seed yields of the nutrient omission treatments will be feasible for the sites where they were nonresponsive to RMOR.

Transcriptome Analysis of Porphyrin-Accumulated and X-Ray-Irradiated Cell Cultures under Limited Proliferation and Non-Lethal Conditions.

5-Aminolevulinic acid (ALA) is a precursor of the photosensitizer used in photodynamic therapy. It accumulates in tumor cells and subsequently metabolizes to protoporphyrin IX (PpIX), which generates singlet oxygen after light irradiation. PpIX enhances the generation of reactive oxygen species following physicochemical interactions with X-rays. ALA-based treatment using fractionated doses of irradiation suppressed tumor growth in a mouse melanoma model. To study the transcriptomic effects of PpIX, microarray analyses were conducted using HeLa cells with limited proliferation capacity. Based on the p-values (p < 0.01), we selected genes showing altered expression in each treatment group with reference to the non-treatment (NT) group. We detected 290, 196 and 28 upregulated genes, as well as 203, 146 and 36 downregulated genes after a 6 h-long PpIX treatment (1 μg/mL) prior to 3 Gy X-ray irradiation (PpIX-XT), 3 Gy X-ray irradiation alone (XT) and PpIX treatment alone (PpIXT), respectively. Functional analysis revealed that a majority of the regulated genes in the XT and PpIX-XT groups were related to cell-cycle arrest. The XT and PpIX-XT groups differed in the quantity, but not in the quality of their gene expression. The combined effect of PpIX and X-ray irradiation sensitized HeLa cells to X-ray treatment.

Long-Term Manure Impacts on Soil Aggregates and Aggregate-Associated Carbon and Nitrogen

Long-term studies document that soil properties influenced by management practices occur slowly. The objectives of this study were to evaluate 70 yr of manure (M) and commercial fertilizer (F) additions and moldboard plowing on soil organic C (SOC), soil total N (STN), water-stable aggregates (WSA), and aggregate-associated C and N. The Knorr–Holden plots have been in furrow irrigated continuous corn (Zea mays L.) since 1912 on a Tripp sandy loam (coarse-silty, mixed, superactive, mesic Aridic Haplustoll). Soil samples were collected from the 0- to 5-, 5- to 10-, 10- to 15-, and 15- to 30-cm depths in 2011. Soils were fractionated by wet sieving into four aggregate-size classes (>1000, 500–1000, 250–500, and 53–250 μm). Continuous M amendment increased the SOC in the 0- to 30-cm depth approximately 1.7-fold compared with the F treatment. The combination of F + M further increased SOC in the 0- to 15-cm depth by approximately 36% for the M treatment receiving 90 kg N ha−1 of F (90 + M) and by 16% for the M treatment receiving 180 kg N ha−1 of F (180 + M) compared with the 15- to 30-cm depth. Macroaggregates increased with M and F + M when compared with F with the corresponding increase in microaggregate quantities associated with the F and no-N treatment. In the 0- to 30-cm depth, microaggregates were approximately 1.8 to 4.9 times greater than the macroaggregates. Aggregate-associated C masses were greater in microaggregates than in macroaggregates, which reflects greater amounts of microaggregates present in the soil. A significant, positive correlation was observed between SOC and aggregate-associated C. Overall, the addition of manure-based amendments, with or without F, increased SOC and enhanced aggregate stability.

Antitumor effects of high-temperature hyperthermia on a glioma rat model.

High-temperature hyperthermia (HTH) is an established treatment option for cancer. The aim of the present study was to reveal the exact correlation between HTH at temperatures of 50–70°C and the resulting antitumor effects, using a glioma rat model. In the 60°C (T-60) and 70°C (T-70) HTH groups, tumor growth rates were significantly suppressed compared with those in the nontreatment (NT) group. In the 50°C (T-50) HTH group, tumor growth rates were not suppressed compared with those in the NT group. The numbers of terminal dUTP nick-end labeling-positive cells in tumor tissue were significantly higher in the T-50, T-60 and T-70 groups than those in the NT group. The Ki-67-positive areas were significantly decreased in the T-70 group compared with those in the NT and T-60 groups. Our data indicate that HTH at 60 and 70°C suppresses tumor growth in a glioma rat model. In particular, cell proliferation was significantly suppressed by HTH at 70°C. However, differences in the mechanism of action of HTH at 60 and 70°C were observed.

Properties of soils in the Swedish long-term fertility experiments: VII. Changes in topsoil and upper subsoil at Örja and Fors after 50 years of nitrogen fertilization and manure application

We tested the hypothesis whether fertilization has an impact on subsoil development using data from two long-term soil fertility experiments. We chose treatments without nitrogen (N) and high N fertilizer addition in two crop rotations with and without ley and farmyard manure application. The soil properties measured included soil organic matter, microbial composition, aggregate stability, readily dispersible clay and micronutrient content in topsoil (0–30 cm) and upper subsoil (30–40 cm). Studies of two adjacent soil profiles revealed that the upper subsoil of an N-fertilized treatment had more soil organic matter, darker colour, more aggregation, more fine roots and was 10 cm thicker than that of the no-N treatment. This pronounced subsoil development in treatments with higher yields (high N input) was corroborated by carbon mass determinations based on systematic sampling including bulk density. Soil organic matter contents were higher in N-fertilized than unfertilized treatments, either with or without manure. Nitrogen fertilization caused distinct differences in microbial composition at one study site. Phospholipid fatty acid analysis revealed: (1) that mineral N fertilizer promoted nitrifiers; and (2) that bacteria were favoured over fungi in treatments with N supply probably due to nitrogen-rich crop residues. Soil aggregate stability (water dispersion) was correlated to soil organic matter and clay content. We also tested the hypothesis whether trace element contents in the top- and subsoil were affected by N fertilization through removal by large yields. Despite long-term depletion, crop removal of micronutrients was too small to cause significant differences in soil between treatments.

Evaluating regional mean optimal nitrogen rates in combination with indigenous nitrogen supply for rice production

Nitrogen (N) is an essential nutrient that requires careful management in intensive rice systems, since insufficient amounts might result in yield losses, and excessive application might harm the environment. However, farmers often tend to apply a large excess of N fertilizer to ensure high rice yields, primarily because of the absence of reliable methods to estimate optimal N application rates. Therefore, a large-scale study comprising 514 field experiments for rice was conducted in seven rice regions (totaling 1.253millionha) in Hubei province, Central China. We (i) evaluated yield responses to different N application levels, (ii) established indigenous soil N supply (INS) classification systems for different rice regions by identifying and using the preferable predictor of INS, and (iii) determined the optimal N application rates for each region based on regional mean optimal N rates (RMONR) in combination with INS. In all of the rice regions, rice yields were significantly higher in plots receiving N than in plots without N (termed no-N plots). The highest yields were obtained in plots receiving medium nitrogen (MN) treatment, where the average partial factor productivity (PFPN) and agronomic efficiency (AEN) were 50.4kggrainkg−1N and 12.5kggrainkg−1N, respectively. Yield responses of rice to N fertilizer were different among different rice regions because of regional variations in climatic conditions and soil fertility. A significant positive relationship between grain yield with and without N fertilizer also proved an important effect of INS on yield response to N fertilizer. On the basis of regression models, relative yields of 90%, 80%, 70%, 60%, and 50% were used as the critical values to obtain INS classifications, which were estimated by the yield of the no-N treatment but not by alkaline hydrolyzable-N. An obvious increasing trend of economic optimum N rate (EONR) with decreasing INS (from Class 1 to Class 6) was found for each rice region. Averaged across all rice regions of Hubei province, EONR was 150kgha−1, which was lower than the N application rate for the MN treatment of 171kgha−1. The results indicated that the N application rate recommended by local rice technicians could be cut by 12% (1–18% in different rice regions) without any loss of yield. In conclusion, the recommended N fertilizer application, based on RMONR in combination with INS, is feasible for regional rice production in China and other countries that have large numbers of small farmland areas and where agricultural testing equipment is absent or less modern.

Effects of Presorting on Stress Responses at Loading and Unloading and the Impact on Transport Losses from Market-Weight Pigs

The objective of this study was to determine the effects of presorting before loading on stress responses and transport losses at the slaughter facility in the market-weight pig. A total of 5,802 pigs (n = 33 loads) were used in a randomized complete block design with 2 treatments. The presorted (PRE) and not presorted (NON) treatments each had 292 pigs/pen (0.65 m2/pig). For the PRE treatment, internal swing gates were used to presort pigs manually 18 h before loading, whereas pigs in the NON treatment were sorted from pen mates at the time of marketing. Treatments were assigned to trailer decks in an alternating manner. Data were analyzed using generalized linear mixed model methodology, and loading time was analyzed using mixed model procedures. Loading time differed (P 0.05) different. There were no (P > 0.05) differences between treatments for total losses at the slaughter facility. Two pigs in the PRE treatment and zero pigs in the NON treatment were classified as dead on arrival. In conclusion, presorting market-weight pigs reduced loading time and some stress responses on farm; however, no treatment differences were observed for stress responses or transport losses at the slaughter facility.

The Effects of an Early Physical Therapy Intervention for Very Preterm, Very Low Birth Weight Infants: A Randomized Controlled Clinical Trial

A randomized controlled clinical trial was used to investigate effects of physical therapy (PT) intervention on motor outcome of infants born very preterm with very low birth weight (VLBW). Seventy-two infants born very preterm with VLBW were randomly assigned to a nontreatment (NT) (n = 38) or treatment (T) (n = 34) group. The T group received developmental PT from birth until four months corrected age (CA) weekdays during the infant's neonatal stay and on a needs- and problem-orientated basis thereafter. The NT group received no intervention. Both groups were assessed at four months CA using the Alberta Infant Motor Scale (AIMS) as was a control group of 14 infants born full term. Parental compliance was measured using a parent questionnaire. PT intervention had no significant effect on the T group's motor performance. However, no T group subjects had abnormal motor development at four months CA when compared to the NT group (16%) and the control group (14%) (p = 0.09). The T group subjects with high levels of parental compliance had better scores on the AIMS than those with lower parental compliance (p = 0.05). PT intervention does not significantly affect motor performance of infants born very preterm with VLBW at four months CA. Parental compliance and intervention frequency may have influenced the outcome. Preliminary evidence suggests that neonatal and early PT may reduce the incidence of motor delay among infants born very preterm with VLBW. Follow-up of this group is recommended to ascertain the long-term benefits of this type of early PT.

Contribution of di-nitrogen fixation by pea to the productivity and N budget of a wheat-based cropping system

The productivity and N budget of three crop rotations were determined in a field study beginning in 1997. A duplicate experiment was initiated in 1998; each experiment lasted 3 years. The rotations were: continuous wheat (WWW), oilseed rape-wheat-wheat (RWW) and pea-wheat-wheat (PWW). Wheat and oilseed rape received 0 or 60 kg N/ha, apart from fertilized wheat following pea, which received 22·5 kg N/ha, and in the third year of the rotation all plots received 60 kg N/ha. Peak N2 fixation by pea averaged 86 kg N/ha and grain N offtake was 74 kg N/ha. In the spring following the unfertilized crops the trend for soil NO3-N was: pea&gt;oilseed rape&gt;wheat. The yields of second and third phase wheat followed the order: PWW&gt;WWW&gt;RWW. The superior yield of second phase wheat following pea is attributed to greater availability of N, mainly below the 25 cm depth of soil. Yields of second phase wheat of the other rotations showed no response to N fertilizer, probably because of dry surface soil in those years. Nitrogen deficits of the no-N treatments over the rotation cycle were 31 kg/ha for PWW and RWW and 87 kg/ha for WWW. Application of N fertilizer reduced the N deficit to 13 kg/ha for PWW and resulted in N gains of 22 kg/ha for WWW and 82 kg/ha for RWW. Oilseed rape yields of this study were much lower than normal for the region, thus N removal in the grain was low. It is concluded that pea is superior to oilseed rape as a break crop, and to maintain N balance through the rotation, wheat following pea required about 20 kg/ha less fertilizer N than was applied to wheat following non-legume crops.

Characteristics of root growth and water uptake from soil in upland rice and maize under water stress

A field experiment was conducted to characterize root growth and water uptake from soil layers with different N levels by upland rice (Oryza sativa L.) and maize (Zea mays L.) under severe water stress (no water supply) and mild water stress (intermittent water supply). Under mild stress conditions, medium N application led to the increase of the total root length but to the decrease of the root length/leaf area ratio compared with the no-N treatment in rice. Water was extracted from soil layers in a pattern approximately proportional to the root length distribution under mild stress. Both in rice and maize, a major portion of the water was extracted from the 0–20 cm depth. Application of N increased the total water uptake, which was attributed to the greater root length and higher specific water extraction rate per unit length of root. Specific water extraction rate can vary to some extent, depending on the transpiration demand of the shoots. In rice, water uptake, dry matter production in shoot, and root length were largely suppressed under severe stress compared with mild stress. In maize, water uptake under severe stress was maintained at a level similar to that under mild stress. This was attributed to the higher extraction from the deep soil below the 40 cm depth, which was supported by the increased root distribution and increased specific water extraction rate per unit root length at the depth under severe stress compared with mild stress. The lower water-capturing capacity of rice than that of maize under severe stress was characterized by a lower response to the enhancement of the morphological growth of the roots in deeper soil layers and the limited ability of water extraction per unit length of root, especially in the deeper layers.

Soil development on loess substrate in central Germany — results of a long-term trial on soil formation§

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Santalum album: Kernel Composition, Morphological and Nutrient Characteristics of Pre-parasitic Seedlings under Various Nutrient Regimes

Abstract Omission of all nutrients or individual minerals (N, K, P, S, Ca) from the growth medium of pre-parasiticSantalum albumseedlings produced significant morphological effects. Compared with fully fertilized seedlings, shoot and root length, leaf area, leaf length and width, leaf number, internode length, shoot length/root length ratio, chlorophyll levels, fresh mass and dry mass were all reduced; leaf thickness increased and stomatal numbers, petiole lengths, root lengths and haustorial numbers showed variable but significant responses. Mineral-specific deficiency symptoms were evident in all omission treatments after 3 months. Treatments in which N, K or all minerals were omitted had the greatest dwarfing effect and increase in height and leaf number ceased after 3 months: only seedlings with no added nutrients (dependent on kernel nutrition) were healthy. The mineral content of no-nutrient seedlings approximated that in kernels. The distribution of minerals between plant parts for each treatment is given. K concentrations and K/Ca ratios were relatively high in leaves of seedlings which received treatments containing K, especially when Ca was absent. A high K/Ca ratio may be inherent inS. albumseedlings rather than acquired after subsequent host connection. All fully fertilized seedlings developed haustoria within 3 months suggesting readiness for early host attachment. Seedlings in no-nutrient, no-N, no-K or no-P treatments had fewer haustoria.

629 PB 481 RESPONSE OF VEGETABLES, N SOURCES AND FALL COVER CROPS ON YIELDS, N ACCUMULATION AND SOIL INORGANIC N

Broccoli, potatoes, cucumbers and green peas were fertilized respectively with 241, 168, 168 and 28 kg N ha-1. The N accumulation was equivalent to the fertilizer application rates for the broccoli, potatoes and cucumbers while the peas accumulated 321 kg N ha-1. Vegetable yields were not affected by previous cereal rye cover crops when compared to the fallow control. Cover crops following broccoli accumulated the least and peas the most N. Inorganic N in the top 30 cm at harvest were significantly different between vegetables, but not in the 30-60 cm depth. Chicken manure and ammonium nitrate as N sources were compared. Broccoli was the test crop and was fertilized with both sources at 241 kg N ha-1. Broccoli yields and N accumulation were different between sources of N and between N and no-N treatments. Inorganic N leaching was greatest with ammonium nitrate fertilization and chicken manure was similar to the no-N fertilizer treatment.

Effect of seed rate and application of N fertilizer on grain yield and N uptake of rice under intermediate deepwater conditions (15–50 cm)

SUMMARYIn an intermediate deepwater (15–50 cm) situation, the number of tillers increased with increase of nitrogen fertilizer from 0 to 40 and 80 kg/ha and of seed rate from 100 to 200, 300 and 400 seeds/m2. The tiller mortality due to higher water depth was higher under no-N treatment and under higher seed rates. The number of panicles and grain yield increased significantly with increase in N. Similarly, an increase in the seed rate increased the number of panicles and decreased the number of grains per panicle and panicle weight. The grain yields of the different seed rates were similar. The interaction between N levels and seed rates was not significant.