A comparative analysis of the growth of sweet and forage sorghum crops. I. Dry matter production, phenology and morphology

1986 ◽  
Vol 37 (5) ◽  
pp. 495 ◽  
Author(s):  
R Ferraris ◽  
DA Charles-Edwards
Keyword(s):  
Dry Matter ◽  
Leaf Tissue ◽  
Sowing Date ◽  
High Density ◽  
Dry Matter Production ◽  
Morphological Development ◽  
Forage Sorghum ◽  
The Third ◽  
Matter Production ◽  
Use Efficiency

A sweet sorghum (cv. Wray) and a forage sorghum (cv. Silk) were grown in south-east Queensland without water deficit at two densities in 0.75 m rows on four occasions between late September and mid January. Tiller and branch numbers, and dry matter production, were recorded at appearance of the third leaf ligule, panicle initiation, anthesis, soft-dough stage, maturity and 3 weeks after maturity. Light interception was measured every 2 weeks. The time between all the studied phenological events up to anthesis was shortened with delay in sowing date except for that between appearance of the third ligule and initiation in cv. Silk. The time between anthesis and maturity lengthened with the delay in sowing date of both cultivars. Rate of development was a function of ambient temperature to the third ligule stage and again during maturation. Tiller and branch production were greatest in cv. Silk, decreased with delay in sowing date for both sorghums and was increased by the high density. The estimated assimilate flux required to sustain basal tillers was substantially lower in cv. Silk than in cv. Wray. This flux increased with temperature. In early sown crops, dry matter yields of cv. Wray were greater than those of cv. Silk. Close spacing increased dry matter yields up to anthesis, but by maturity the effect of spacing had been reduced. Cv. Wray produced a larger leaf canopy more rapidly than cv. Silk, although the partitioning of dry matter to leaf tissue only differed between cultivars after canopy closure. The efficiency with which crops used intercepted light energy to produce new above-ground dry matter changed during their ontogeny. It is suggested that early changes in efficiency were a consequence of altered partitioning to roots. The effect of sowing date and spacing on efficiency of light use was slight until the maturation phase, when efficiency decreased with delay in sowing date and at high density. Water use efficiency differed in a similar way to light use efficiency. The relationships found in this study indicate that sorghum growth models need to recognise differences in the morphological development of sorghum types.

Nitrogen fixation by irrigated lucerne during the first three years after establishment

1995 ◽  
Vol 46 (7) ◽  
pp. 1401 ◽  
Author(s):  
RR Gault ◽  
MB Peoples ◽  
GL Turner ◽  
DM Lilley ◽  
J Brockwell ◽  
...  
Keyword(s):  
Soil Nitrogen ◽  
N2 Fixation ◽  
Dry Matter ◽  
Growing Season ◽  
15N Natural Abundance ◽  
Natural Abundance ◽  
Dry Matter Production ◽  
Available Phosphorus ◽  
The Third ◽  
Matter Production

Nodulation, N2 fixation (estimated by 15N natural abundance methods) and dry matter production were studied in a lucerne (Medicago sativa) crop managed for hay production at Ginninderra Experiment Station, A.C .T. Measurements were taken in the year of establishment and during two subsequent growing seasons. There were three treatments: (1) no inoculation and no annual fertilizer applied, (2) initial inoculation and superphosphate applied annually, (3) no inoculation, superphosphate applied annually and ammonium sulfate periodically. Before planting and after each growth season, soil was analysed for extractable mineral nitrogen, total nitrogen and the 15N natural abundance of this nitrogen, to the depth explored by lucerne roots. Before planting, no appropriate root-nodule bacteria (Rhizobium meliloti) were detected in the soil and initially plants were nodulated only in the inoculated treatment. Thereafter nodulation increased on the other treatments. Eight months after sowing there were no differences between treatments in numbers of R. meliloti g-l soil or in nodulation. In the third growing season, almost 30 kg ha-1 (dry wt) of nodules were recovered to a depth of 25 cm. These nodules were primarily located on fine, ephemeral roots and many appeared to be renewed after cutting of the lucerne. In the year of establishment, dry matter yields (0% moisture) totalled 3 to 4 t ha-1 in three hay cuts. In succeeding years, total yields were in the range 10 to 13 t ha-1 in four or five cuts per season. Nitrogen removed in the harvested lucerne reached 340 to 410 kg N ha-lyr-l in the second and third years and between 65 and 96% of this N arose from N2 fixation, depending on the method of calculation used. Poorer dry matter production and N2 fixation in treatment 1 in the third growing season was attributed to an insufficient supply of available phosphorus. Fixed N removed in Lucerne hay from treatment 2 totalled at least 640 kg N ha-1 in the three years of the experiment. Also, there were substantial increases in soil nitrogen due to lucerne growth. Although soil compaction made the quantification difficult, at the end of the experiment it was estimated that there was at least an extra 800 kg N ha-1 in the total soil nitrogen under lucerne compared to strips of Phalaris aquatica grown between the lucerne plots. It was concluded that lucerne contributed at least the same amount of fixed nitrogen to the soil as was being removed in the harvested hay.

Discrimination in Carbon Isotopes of Leaves Correlates With Water-Use Efficiency of Field-Grown Peanut Cultivars

1988 ◽  
Vol 15 (6) ◽  
pp. 815 ◽  
Author(s):  
GC Wright ◽  
KT Hubick ◽  
GD Farquhar
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Dry Matter Yield ◽  
Strong Negative Correlation ◽  
Matter Production ◽  
Whole Plant ◽  
Use Efficiency ◽  
The Relationship

Variation in water-use efficiency (W, g of total dry matter produced/kg water used), and its correlation with cultivar isotope discrimination in leaves (Δ) was assessed in peanut plants grown in small canopies in the field. Plants were grown in separate minilysimeters that were both embedded in the ground and positioned above the crop. Differences among cultivars were found in W and � and the relationship between W and Δ was compared for plants grown in open and closed canopies. Genetic variability in W in plants grown in the field under non-limiting water conditions was demonstrated, with Tifton-8, of Virginia habit, having the highest W (3.71 g/kg) and Rangkasbitung, an Indonesian cultivar of Spanish habit, the lowest (2.46 g/ kg). Variability in W was due to variation in total dry matter production more than that of water use. A strong negative correlation was found between Δ and W, and also between Δ and total dry matter. The relationship between whole plant W, including roots, and Δ was stronger than that between shoot W, without roots and Δ. The improvement occurred because of variation among cultivars in the root to shoot ratio. This highlights the importance of taking account of root dry matter in studies concerning W. There were significant differences in W and Δ between plants in pots above-ground compared to pots in the ground, with above-ground plants having significantly lower values of both W and Δ. The ranking of W and Δ among cultivars was not affected by the contrast in environment, which suggests these parameters are under strong genetic control. Total above-ground dry matter yield at maturity was negatively correlated with Δ, while pod yield was not. It appears a negative association between harvest index and Δ may exist; however not all cultivars used in this and other studies follow this response. Both water-use efficiency, Wand total dry matter production are negatively correlated with Δ in leaves of peanut plants grown in small canopies in the field. Measurement of Δ may prove a useful trait for selecting cultivars with improved W and total dry matter yield under field conditions.

scholarly journals Effect of K-N-Humates on Dry Matter Production and Nutrient Use Efficiency of Maize in Sarawak, Malaysia

2010 ◽  
Vol 10 ◽  
pp. 1282-1292 ◽  
Author(s):  
Auldry Chaddy Petrus ◽  
Osumanu Haruna Ahmed ◽  
Ab Majid Nik Muhamad ◽  
Hassan Mohammad Nasir ◽  
Make Jiwan
Keyword(s):  
Humic Substances ◽  
Dry Matter ◽  
Nutrient Use Efficiency ◽  
Inorganic Fertilizer ◽  
Organic Fertilizers ◽  
Dry Matter Production ◽  
Nutrient Use ◽  
Matter Production ◽  
Standard Procedures ◽  
Use Efficiency

Agricultural waste, such as sago waste (SW), is one of the sources of pollution to streams and rivers in Sarawak, particularly those situated near sago processing plants. In addition, unbalanced and excessive use of chemical fertilizers can cause soil and water pollution. Humic substances can be used as organic fertilizers, which reduce pollution. The objectives of this study were to produce K- and ammonium-based organic fertilizer from composted SW and to determine the efficiency of the organic-based fertilizer produced. Humic substances were isolated using standard procedures. Liquid fertilizers were formulated except for T2 (NPK fertilizer), which was in solid form. There were six treatments with three replications. Organic fertilizers were applied to soil in pots on the 10th day after sowing (DAS), but on the 28th DAS, only plants of T2 were fertilized. The plant samples were harvested on the 57th DAS during the tassel stage. The dry matter of plant parts (leaves, stems, and roots) were determined and analyzed for N, P, and K using standard procedures. Soil of every treatment was also analyzed for exchangeable K, Ca, Mg, and Na, organic matter, organic carbon, available P, pH, total N, P, nitrate and ammonium contents using standard procedures. Treatments with humin (T5 and T6) showed remarkable results on dry matter production; N, P, and K contents; their uptake; as well as their use efficiency by maize. The inclusion of humin might have loosened the soil and increased the soil porosity, hence the better growth of the plants. Humin plus inorganic fertilizer provided additional nutrients for the plants. The addition of inorganic fertilizer into compost is a combination of quick and slow release sources, which supplies N throughout the crop growth period. Common fertilization by surface application of T2 without any additives (acidic and high CEC materials) causes N and K to be easily lost. High Ca in the soil may have reacted with phosphate from fertilizer to form Ca phosphate, an insoluble compound of phosphate that is generally not available to plants, especially roots. Mixing soil with humin produced from composted SW before application of fertilizers (T5 and T6) significantly increased maize dry matter production and nutrient use efficiency. Additionally, this practice does not only improve N, P, and K use efficiency, but it also helps to reduce the use of N-, P-, and K-based fertilizers by 50%.

A relation between wool production per animal and annual pasture dry matter production per animal

1982 ◽  
Vol 33 (4) ◽  
pp. 705 ◽  
Author(s):  
BA Rowe
Keyword(s):  
Dry Matter ◽  
Simple Relation ◽  
Dry Matter Production ◽  
First Year ◽  
Stocking Rate ◽  
Pasture Production ◽  
Wool Production ◽  
The Third ◽  
Matter Production ◽  
Curvilinear Relation

A simple relation between the annual wool production per animal (y) and the amount of pasture dry matter produced per animal (x) was derived and tested using the results from a grazing experiment in which the effects of superphosphate and stocking rate on wool and pasture dry matter production were measured from pastures which were continuously grazed by Merino wethers for 3 years. The linear relation, y = a + b/x, accounted for 63% of the variance in wool production per animal in the first year, 82 % in the second and 97 % in the third. Exclusion of an outlier from the first year results increased the variance accounted for to 85 %. This model is simpler and more precise than some others that have been published. It is also consistent with the curvilinear relation between production per animal (y) and pasture production per animal (x).

Nitrogen-limited light use efficiency in wheat crop simulators: comparing three model approaches

2015 ◽  
Vol 154 (6) ◽  
pp. 1090-1101 ◽  
Author(s):  
A. M. RATJEN ◽  
H. KAGE
Keyword(s):  
Dry Matter ◽  
Dry Matter Production ◽  
Wheat Crop ◽  
Light Use Efficiency ◽  
Data Set ◽  
Area Index ◽  
N Concentration ◽  
Matter Production ◽  
Use Efficiency ◽  
Critical N Concentration

SUMMARYThree different explanatory indicators for reduced light use efficiency (LUE) under limited nitrogen (N) supply were evaluated. The indicators can be used to adapt dry matter production of crop simulators to N-limited growth conditions. The first indicator, nitrogen factor (NFAC), originates from the CERES-Wheat model and calculates the critical N concentration of the shoot as a function of phenological development. The second indicator, N nutrition index (NNI), calculates a critical N concentration as a function of shoot dry matter. The third indicator, specific leaf nitrogen (SLN) index (SLNI), has been newly developed. It compares the actual SLN with the maximum SLN (SLNmax). The latter is calculated as a function of the green area index (GAI). The comparison was based on growth curves and fitted to empirical data, and was carried out independently from a dynamic crop model. The data set included four growing seasons (2004–2006, 2012) in Northern Germany and seven modern bread wheat cultivars with varying N fertilization levels (0–320 kg N/ha). The influence of N shortage on LUE was evaluated from the beginning of stem elongation until flowering. With the exception of 2005, the highest productivity was observed for the highest N level. A moderate N shortage primarily reduced GAI and therefore light interception, while LUE remained stable under moderate N shortage. The relative LUE (rLUE) of a specific day was defined as the ratio of actual to maximal LUE. None of the indicators was proportional to rLUE, but the relationships were described well by quadratic plateau curves. The correlation between simulated and measured rLUE was significant for all explanatory indicators, but different in terms of mean absolute error and coefficient of determination (R2). The performance of SLNI and NNI was similar, but the goodness of prediction was much lower for NFAC. Compared with NNI and NFAC, SLNI corresponded to leaf N and was therefore sensitive to N translocation from leaves to growing grains during the reproductive stage. For this reason, SLNI may have the potential to improve simulation of dry matter production in wheat crop simulators.

Sign in / Sign up

Export Citation Format

Share Document