Differences In Dry Matter Production Research Articles

Differences in dry matter production and grain yield of maize (Zea mays L.) cultivars with contrasting nitrogen efficiency

ABSTRACT We aimed to investigate the differences in dry matter accumulation (DMA), distribution, remobilisation, and yield of maize cultivars with contrasting nitrogen efficiency responses to nitrogen application rates. Nitrogen fertiliser increased DMA, crop growth rate (CGR), redistribution of pre-silking dry matter, and accumulation of post-silking dry matter while reducing the root/shoot biomass ratio to substantially increase biomass yield and final maize grain yield. Higher final theoretical biomass yield, maximum increasing rate (MIR), and average increasing rate, later days to MIR, longer duration of rapid growth period, higher ratio of vegetative organs, and rational dry matter distribution aboveground and belowground contribute to higher DMA and CGR in the later growth stage, and higher assimilated dry matter into grain and biomass yield to finally obtain higher grain yield for N-efficient maize cultivar. The N-efficient cultivar had obvious advantages on grain yield compared with N-inefficient cultivar caused by higher dry matter average increasing rate and biomass and kernels per ear, while the advantages increased first, then decreased with higher N rates, and the highest value was observed at 247.5 kg N ha−1. Therefore, selecting N-efficient maize improves maize yield per unit area while reducing N fertiliser supply, especially at low N application rates.

Nitrogen‐15 evaluation of fertilizer placement at planting for corn production

AbstractNumerous studies have been reported to ascertain the benefits of starter fertilization for corn (Zea mays L.) production, but most rely on data collected by measuring early growth or grain yield at harvest. As a more conclusive evaluation, five field trials were conducted using 15N‐labeled urea‐ammonium nitrate (UAN) solution (90 kg N ha−1) to compare single and dual subsurface band placement, as well as surface dribble and broadcasting with incorporation. Significant differences in dry matter production and total N uptake occurred between fertilized and unfertilized treatments, but not among the different placements studied. In contrast, fertilizer 15N uptake efficiency (F15NUE) tended to be greater for either type of subsurface banding than for the dribble treatment, demonstrating the added sensitivity that can be achieved through isotopic measurements. More importantly, band placement consistently outperformed broadcasting, according to estimates of F15NUE for total aboveground biomass that ranged from 11% to 46% when UAN was banded and from 7% to 34% for broadcast applications.

Produção, composição química e eficiência da utilização de nitogênio aplicado de pastagens de BRS Kurumi

ABSTRACT: The objective was to evaluate the effect of nitrogen fertilization levels on productivity, and nutritional value of BRS Kurumi managed at different residue heights during rainy and dry periods of the year. The pasture was managed in three residue heights (20, 35, and 50 cm) and three nitrogen fertilization levels (0, 100, and 200 kg N/ha/year) during the rainy and dry seasons. When the height of the grass of each plot reached 80 cm, the Kurumi was cut manually at the pre-established residue heights. Around 89% of the dry matter (DM) production was observed during the rainy season. The residue height of 35 cm together with doses of 100 or 200 kg N/ha/year, and the residue height of 20 cm, with a dose of 100 kg N/ha/year were the treatments that had the highest DM production during the rainy period. No differences in DM production were observed between tested treatments during the dry period. The Kurumi cultivated during the dry period had the highest content of neutral detergent fiber and lowest digestibility. The Kurumi managed with residue heights of 20 and 35 cm and fertilized with 100 kg N/ha had the highest values of efficiency of utilization applied nitrogen. The use of 20 or 35 cm of residue height and 100 kg of N/ha/year is recommended to obtain greater biomass production and nutrients, nutritional quality, and nitrogen use efficiency.

Effect of nitrogen application on the expression of drought-induced root plasticity of upland NERICA rice

ABSTRACT This study evaluated the effect of three N fertilization levels 60 (low), 120 (medium), and 180 (high) kg N ha−1 and soil moisture content gradients created by a line-source sprinkler on the expression of plasticity in lateral root branching and dry matter production (DMP) of upland new rice for Africa (NERICA) 1 and 4. There were no significant differences in DMP between NERICA 1 and 4 under well-watered, mild drought, and severe drought conditions regardless of N level. In contrast, under moderate drought (12–21% v/v of soil moisture content [SMC] in 2011 and 16–24% v/v of SMC in 2012), NERICA 1 had significantly higher shoot dry weight, total root length (TRL), lateral root length, and branching index than NERICA 4 at medium and high N; however, there was no significant difference between the two NERICAs in DMP at low N. TRL of NERICA 1 was significantly higher under moderate drought than well-watered conditions, but only with medium and high N. Regardless of N level, moderate drought did not enhance NERICA 4’s root system. Thus, NERICA 1’s root system exhibited plastic development, promoting lateral root branching at medium and high N. These morphological changes were associated with the greater DMP in NERICA 1 than NERICA 4 under moderate drought, whereas the lack of such plasticity at low N meant genotypic differences in DMP were obscured. Our findings implied that N application can improve upland NERICA productivity under moderate drought conditions, but differences in variety and field conditions may influence efficacy.

Summer production and survival of perennial ryegrass (Lolium perenne) and tall fescue (Festuca arundinacea) genotypes in northern Victoria under differing irrigation management

Perennial ryegrass (Lolium perenne L.) is the predominant perennial forage species used in temperate irrigated dairy-production systems in Australia. However, when temperatures are high, even with optimal irrigation strategies and nutrient inputs, dry matter (DM) production can be compromised. This research investigated the effects of perennial ryegrass and tall fescue genotypes and summer irrigation on (DM) production and survival. Ten perennial ryegrass cultivars, three hybrid ryegrasses and two cultivars of tall fescue (Festuca arundinacea (Schreb) Darbysh.) were sown in northern Victoria, Australia, in May 2014, and were managed under full irrigation or restricted irrigation (no irrigation between late December and mid-March) over a 3-year period. Measurements included net pasture accumulation (DM production), sward density (plant frequency) and water-soluble carbohydrate concentration. Apart from the expected differences in DM yield over the summer period between full irrigation and restricted irrigation, there were few differences in DM production among perennial ryegrass or tall fescue cultivars. Plant frequency declined significantly under restricted irrigation in Years 2 and 3 compared with full irrigation but there were no differences among perennial ryegrass cultivars. In Year 2, plant frequency was higher in the tall fescue cultivars than the ryegrass cultivars. The recovery pattern in DM production following recommencement of irrigation in mid-March (autumn) varied across years. In Year 1, plants recovered rapidly once irrigation recommenced in autumn. However, in Years 2 and 3, autumn and winter pasture accumulation under restricted irrigation was 30–35% less than under full irrigation. These differences were possibly related to decreases in plant frequency, as well as to differences in the amounts of residual pasture mass (or carbohydrate reserves) present when growth ceased. Analyses of the water-soluble carbohydrate concentrations in the pseudostem during summer and autumn in Year 3 showed differences in total water-soluble carbohydrate and in fructan and sucrose concentrations between irrigation treatments but no consistent differences among genotypes.

Nitrate leaching losses during pasture renewal – Effects of treading, urine, forages and tillage.

Pasture renewal is a key component of intensive temperate grassland farming. This practice is performed to improve pasture yields, but it may increase nitrate (NO3−) leaching losses, which can impact on water quality. Farmers face many choices when renewing pasture, however, there is limited information to guide decisions to reduce leaching losses.An experiment was established to study how different management practices and grazing affect biomass production and NO3− leaching during pasture renewal on a heavy soil. Long-term pasture was either re-sown into ryegrass (Lolium perenne) in autumn (GG) or into forage rape (Brassica napus) followed by ryegrass in spring (GCG). Rape was established following ploughing or direct-drilling. Grazing was simulated in winter, whereby split plots ±urine (600 kg N ha−1) and ±treading were established. Nitrate concentrations at 1 m depth were measured with suction cups and drainage predicted using a crop model.Estimated NO3− leaching losses at 1 m depth ranged from 16 to 38 kg N ha−1, with little difference between GCG and GG. However, the risk of future leaching was much greater below GCG plots. At the end of the study, soil NO3− between 0.6 and 1 m ranged from 28 to 130 kg N ha−1 in GCG plots and 1–28 kg N ha−1 in the GG plots. Timing of leaching differed between renewal systems, reflecting the differences in plant N uptake and fallow period. Overall, there was no difference in dry matter production between the two systems. Treading resulted in greater compaction, especially in tilled plots and reduced NO3− leaching by c. 40% – this can be attributed to increased denitrification.Our study demonstrates the complex nature of management and environmental factors and their interaction during pasture renewal. We show that management practices affect the risk and timing of N leaching. Practical implications for farmers are discussed.

ESTABLISHMENT ATTRIBUTES OF Bouteloua curtipendula (Michx.) Torr. POPULATIONS NATIVE TO MEXICO

Large areas of arid and semi-arid grasslands in Mexico are severely damaged. Large areas of high-risk rainfed crops have been abandoned. These problems are the result of constant overgrazing, extraction of firewood, overutilization of valuable species, fire and the practice of subsistence agriculture. The aim of this study was to measure the initial performance of the seedlings, as well as forage production and survival in the second year of nine Bouteloua curtipendula populations native to Mexico in comparison with El Reno, a commercial variety from the US. Plant development was visually estimated and dry matter (DM) production was estimated one year after the establishment. Survival was assessed at the end of the growing season in the following year. The experiment was carried out using a complet randomized blocks experimental design, and differences in vigor between genotypes were analyzed by a permutation test. Significant differences in DM production and plant establishment (P ≤ 0.05) were observed between genotypes. The US commercial variety was the least productive population, exhibiting less vigor during the first year than the rest of the genotypes evaluated. Large diversity in seedling establishment capacity, DM yield and survival was observed in the second year. The Mexican populations 241, NdeM-303, 47 and NdeM-5 were superior for plant establishment and DM production.

異なる播種時期および穂肥量で栽培したハダカムギの乾物生産，収量および 品質特性に関する品種間比較

異なる播種時期および穂肥量で栽培したハダカムギの乾物生産，収量および 品質特性に関する品種間比較

34 網走市の異なる土壌タイプの土壌に生育し,子実収量の異なるコムギの乾物生産と乾物生産過程の解析

34 網走市の異なる土壌タイプの土壌に生育し,子実収量の異なるコムギの乾物生産と乾物生産過程の解析

Differences in dry matter production, grain production, and photosynthetic rate in barley cultivars under long-term salinity

Soil salinity is a major environmental stress causing significant loss of crop productivity. Barley (Hordeum vulgare L.) is one of the few field crops that can grow in salt-affected fields and varietal differences in productivity under salinity conditions were known. To clarify the trait most responsible for grain production under salt stress, barley cultivars that were salt tolerant (OUE812) or salt sensitive (OUC613) were grown from seedling to harvest stage in vermiculite containing various concentrations of NaCl. Dry weight of aboveground parts and grain weight decreased significantly with increasing NaCl concentration. The dry weight of the aboveground parts and grain weight decreased more significantly in OUC613 than in OUE812 for plants treated with 150 mM and 200 mM NaCl. A marked reduction in ripening percentage caused significantly decreased grain production in OUC613 as compared with OUE812. In plants treated with 200 mM NaCl, the photosynthetic rate decreased three weeks after starting the NaCl treatment, but a significant difference between cultivars in photosynthetic rate did not appear until seven weeks of NaCl treatment. OUE812 kept a higher photosynthetic rate during ripening than did OUC613 and dry matter production during the period from ripening to harvest was significantly larger in OUE812 than in OUC613. Keeping a higher photosynthetic rate might have contributed to higher grain production in OUE812. Higher ripening percentage and higher rate of photosynthesis during ripening might be target traits in breeding to improve the tolerance of barley to long-term salt stress.

Germination and initial development of Brachiaria brizantha and Brachiaria decumbens on exposure to cadmium, lead and copper

Abstract: The objective was to evaluate the germination and initial development of three cultivars of Brachiaria brizantha and Brachiaria decumbens in the presence of trace elements of Cd, Pb and Cu and quantify the Cd and Cu contents in plant tissue of these species. First, seed germination occurred in towel paper containing cadmium, lead, copper and the control. We calculated the percentage of germination, germination speed index, vigor index and seedling length. Later, the seeds were germinated in soil pots contaminated with Cd and Cu, where the Soil-Plant Analysis Development index (SPAD index) was evaluated, as well as dry matter of shoot and root, and the Cd and Cu metal content in plant tissue was quantified. B. decumbens showed sensitivity to the elements studied, with decreases in all parameters. Cu was the element that caused more toxic effects on germination and early seedling development of the species studied. In contaminated soil, the species studied showed no differences in dry matter production of shoots, but the exposure to Cd and Cu caused reductions in SPAD index in all species. The highest Cd and Cu contents were found in the roots.

Relationship between Phosphorus Accumulation and Dry Matter Production in Soybeans

Six cultivars of soybean were cultivated under various phosphorus (P) application levels, in pots and in fields to clarify the relationship between P accumulation and dry matter production, and that of varietal differences in soybeans. Dry matter production and yield components increased with the increase of P application, especially under P-deficient conditions, and there were varietal differences in dry matter production, yield components, and amount of P accumulation. However, there were significant relationships between dry matter production and P accumulation, and the relationships could be represented by the same regression line regardless of cultivar. There were varietal differences in dry matter production efficiency of accumulated P under a P-deficient condition. These results suggest that either high ability to accumulate P or efficient dry matter production of P is required for stable production under P-deficient conditions. Therefore, selection of cultivars that have high dry matter production efficiency or large root systems, or the development of agricultural management technology that increases the rate of P fertilizer absorption is required for stable production under P-deficient conditions.

EFFECT OF RESIDUAL ROCK PHOSPHATE AND BIOFERTILIZERS (RHIZOBIUM AND BIOPHOSPHATE) AND THEIR COMBINATIONS ON THE PRODUCTIVITY OF Stylosanthes guianensis CIAT 184

The purpose of this research was to evaluate the agronomic effectiveness of rock phosphate, biological fertilizers (Rhizobium and bio-phosphate) and their combinations on dry matter (DM) production, nutrient content and in vitro dry matter digestibility (IVDMD) of Stylosanthes guianensis CIAT 184. This research was conducted at Forage and Pasture Laboratory, Universitas Gadjah Mada, Yogyakarta, Indonesia from February – October 2010. A strip plot design which consisted of two fertilizer factors with three (3) replicates was used. The first factor was the horizontal factor and consisted of four levels of biological fertilizers (Rhizobium and bio-phosphate) namely: M0 = control, M1 = Rhizobium (0.5 g/plot), M2 = bio-phosphate (0.6 g/plot) and M3 = combinations of Rhizobium and bio-phosphate. The second factor was the vertical factor and consisted of three levels of rock phosphate, namely: P0 = control, P1 = 250 kg/ha (32.5 P kg/ha) and P2 = 500 kg/ha (65 P kg/ha). Defoliation was carried out every three months for 9 months. Results of the study showed that there was no significant difference in DM production (kg/ha) amongst treatments. Although the current research showed no significance difference amongs the treatments, DM production increased in the 2nd harvest (12.3%) and 4th harvest (7.1%) between P0 and P1. Combinations treatment P1M2 (21073.63 kg/ha) had the highest average DM production amongs treatments. Statistical analysis followed by Duncan’s new Multiple Range Test (DMRT), showed that rock phosphate can significantly (P<0.05) increase fiber production of Stylosanthes guianensis. It showed that treatment P1 increased crude fiber production by 12.2% from 5864, 47 kg/ha to 6580,19 kg/ha. In addition, tests further revealed that there was a difference between M1 and M2, but had no effect on M0. There was no significant effect on production (kg/ha) of crude protein, phosphorus, nitrogen free extract (NFE) and ash. In conclusion, treatments with rock phosphate and bio-fertilizers tend to increase productivity of Stylosanthes guianensis CIAT 184. (Key words: Stylosanthes guianensis CIAT 184, Rock phosphate, Bio-phosphate, Rhizobium, and In vitro dry matter digestibility)

Effects of elevated CO2 and cyclic drought on potato under varying radiation regimes

Climate change predictions include increased frequency of episodic drought in many potato (Solanum tuberosum L.) producing regions in the world. Quantitative data on potato response to periodic drought under elevated atmospheric carbon dioxide (CO2) conditions is lacking, but is needed to improve crop modeling tools suitable for investigating adaptation strategies. Two experiments E1 and E2 were conducted in sunlit soil-plant-atmosphere research (SPAR) chambers to evaluate effects of short-term drought cycles at ambient and twice-ambient CO2. Experiments were conducted in the same growing season, but at different planting dates in order to further examine effects of variation in solar radiation during the drought periods (daily average photosynthetically active radiation of 43.9molm−2d−1 in E1 and 24.7molm−2d−1 in E2). Drought cycles were applied at post-tuber initiation (R) or at both vegetative and post tuber-initiation (VR) stages. While total dry matter in E1 was nearly twice that of E2 as a result of the radiation differences, relative responses to drought and CO2 were consistent. Total dry matter production was reduced proportionately based on the number of drought cycles, with twice-droughted VR plants producing less biomass than non-droughted controls. Harvest index and the ratio of tuber to total dry matter growth rate increased with drought frequency, suggesting that tuber sink strength was higher for VR plants than R. Harvest index, the ratio of tuber to total plant growth rate, and tuber dry matter for VR and R treated plants were also higher at elevated versus ambient CO2. Water use efficiency for water deficient versus water sufficient plants was correlated with harvest index and also increased at the higher CO2 concentration. As there was also little influence of drought or CO2 on leaf extension characteristics, differences in dry matter production and allometric responses were assumed to predominantly be a function of assimilation rate and carbon partitioning. These results confirm potato drought sensitivity in terms of yield response is influenced by developmental stage and CO2 regardless of light environment, and provide necessary data for calibration and testing modeling tools for climate change studies.

Understanding physiological processes associated with yield–trait relationships in modern wheat varieties

New insights into changes in physiological processes associated with genetic gains in yield potential are essential for improved understanding of yield-limiting factors. Our field study was conducted at two sites with three N levels and 15 modern wheat ( Triticum aestivum L.) varieties. The goal was to evaluate yield components, time courses of dry matter production, and N accumulation among different yield categories, and to determine physiological processes associated with yield–trait relationships. Close correlations were observed between yield and dry matter production after the stem elongation stage, particularly post-anthesis. Similar close correlations were observed between grain yield and N accumulation over the whole growing season, except for the re-greening stage. No positive correlation was found between yield and harvest index. Differences in dry matter production among different yield categories began at anthesis; differences in N accumulation emerged even earlier. We conclude that consistent increases in dry matter production (especially post-anthesis) and N accumulation are crucial for further improvements in wheat yield–trait relationships.

Diferentes fontes de P no desenvolvimento do meloeiro e disponibilidade de fósforo no solo

This work assessed the development of melon crops,and the availability of phosphorus in the soil with the use of biofertilizer phosphate after three cycles of culture. The treatments were distributed into randomized block design with three repetitions, arranged in a factorial 2 x 3 x 7, corresponding to two types of soils (Yellow Latossol and Fluvic Neosol); three sources of phosphorus (triple superphosphate, bio-fertilizer phosphate and rocks) and seven levels of phosphorus (0; 0.5; 1.0; 1.5; 2.0; 2.5; 3.0 of recommended for the culture and for each soil). The triple superphosphate fertilizer, biofertilizer rock phosphate and rock phosphate showed no significant differences in dry matter production, but the biofertilizer was the most available P in both soils after three cycles of the same culture.

Long-term effects of organic manure application on the productivity of winter wheat grown in a crop rotation with maize in Japan

Achieving high productivity using organic manure as a source of N offers new soil management possibilities in intensive agriculture. Our objective was to study the growth response of winter wheat ( Triticum aestivum) to different fertilization regimes in long-term experiments in Japan. Semi-dwarf wheat varieties were grown in crop rotation with maize ( Zea mays) with a high rate of organic manure (OM; 80 t ha −1 yr −1 for >10 years, estimated N application rate is 739 kg N ha −1 yr −1), and standard (SF; 204–252 kg N ha −1 yr −1) or low (LF; 102–126 kg N ha −1 yr −1) rates of inorganic fertilizer for 3 years. We observed greater biomass production in OM than in SF or LF, which was attributable to a higher leaf area index, leaf N status, and stomatal conductance in OM. Grain yield in OM (6.6–8.9 t ha −1) was significantly higher than that in LF (3.5–6.6 t ha −1) for both cultivars, and comparable to that in SF (6.6–8.5 t ha −1). However, the dry matter partitioning during the grain-filling period suggested an imbalance in the sink–source relationship in OM: the number of grains was too large for the assimilation rate. Varietal differences in grain weight in OM resulted from differences in dry matter production during grain filling and, to a lesser extent, differences in grain density. The growth pattern of wheat under intensive manure application should be modified to favor biomass production during the post-anthesis stages. Based on our results, we discuss possible strategies for wheat improvement under high soil fertility in Japan.

Osmotic and ionic effects of various electrolytes on the growth of wheat

Pot experiments were conducted using a sandy loam soil and various electrolyte solutions such as NaCl, CaCl2, Na2SO4, and Hoagland nutrient solution containing all macro- and micro-nutrient elements in appropriate proportions, inducing different electrical conductivity (EC) levels of the soil solution during the growth of Krichauff wheat while the water content in the pot soils was maintained at field capacity. The resulting differences in dry matter production after 40 days of growth clearly indicated the continuous operation of osmotic effect as the EC of the soil solution increased from 0.7 to 41.0 dS/m. However, the osmotic effect became dominant and severely restricted plant growth when the soil solution EC increased above a ‘threshold value’, which was 25 dS/m, corresponding to an osmotic pressure of 900 kPa, in this experiment. Below this EC value, particularly at low EC values, ionic effects due to Na+, Ca2+, SO42–, and Cl– were also evident, but it could not be concluded whether these effects were due to toxicity or ion imbalance. The osmotic effect at EC values above the threshold resulted in greatly reduced water uptake from pot soils, the unused water being in the range 89–96% of the field capacity of the soil. Water use efficiency is a major factor in profitable and sustainable dryland agriculture. Both soil management and selection and breeding of salt-tolerant plants should concentrate on ensuring that the threshold EC value for severe osmotic effects is not reached under field conditions.

Genetic variations in dry matter production and physiological nitrogen use efficiency in rice (&lt;i&gt;Oryza sativa&lt;/i&gt; L.) varieties

The objective of this study was to investigate varietal differences in dry matter production and physiological nitrogen use efficiency (PNUE) using a wide range of rice (Oryza sative L.) varieties at an early growth stage. The results provide useful information for breeding suitable varieties for cultivation under conditions of low soil fertility or with reduced fertilizer use for sustainable agriculture. Thirty-one rice varieties were used, and seedlings were grown under 8 nitrogen treatment conditions. The effects of natural variations in embryo and/or endosperm size on initial growth were controlled for by comparing the relative dry weight (RDW) of nitrogen-treated samples and controls. The rice varieties were classified into 5 groups by cluster analysis. Overall, the present study found that there are wide variations in PNUE among varieties with similar levels of RDW under varying nitrogen conditions. Variations in PNUE were greater under lower nitrogen conditions; in contrast, variations in RDW were greater under higher nitrogen conditions. These data, along with those of other studies, indicate differences in nitrogen use efficiency between Indica- and Japonica-types, upland and lowland varieties, and landraces and improved types.

Estimation of respiratory parameters for rice based on long-term and intermittent measurement of canopy CO 2 exchange rates in the field.

Estimation of respiratory parameters, such as maintenance coefficient and growth conversion efficiency, is important for simulating crop growth. The objective of this study was to estimate respiratory parameters for rice ( Oryza sativa L.) by model analysis based on long-term and intermittent measurement of canopy CO 2 exchange rate (CER) in the field conditions. Canopy CER was intermittently measured in the field conditions for three rice varieties every 30 min from around the panicle initiation stage to maturity in 2004. Based on this measurement, rice respiration model was established and respiratory parameters were estimated by Simplex method. There was a big difference in respiration rate among rice varieties and large seasonal changes as evidenced by the long-term and intermittent measurement of canopy CER. The model explained the varietal difference and seasonal changes in respiration rate without any bias despite that all respiratory parameters, maintenance coefficient and growth conversion efficiency, were fixed for the three varieties. The results indicated that genotypic differences and seasonal changes in respiration rate result not from differences in respiratory parameters, but from differences in dry matter production, its allocation, and the N concentration of each tissue. Estimated respiratory parameters explained well the large variations in the directly measured canopy respiration rate of field grown rice. The model analysis suggested that the varietal differences and seasonal changes in canopy respiration rate were caused by differences in the dynamics of dry matter and nitrogen accumulation in plants.