Shihab Uddin

New South Wales Department of Primary Industries · Wagga Wagga Agricultural Institute

Background and aims While a limited number of studies have investigated cereal-legume temporary intercropping in organic systems, the potential for temporary intercropping to improve soil properties or cash crop yield/quality in conventional systems remains unknown. Methods A field experiment comparing monoculture wheat to wheat with a temporary (...

Deep placement of nutrient enriched organic matter (NEOM) may ameliorate subsoil constraints and improve crop productivity. The mechanism(s) responsible is unclear, e.g. improved nutrient supply, improved soil structure, reduced toxicity or some combination of these. Two glasshouse experiments using PVC columns containing a sodic subsoil were under...

Alkaline dispersive soils dominate crop production throughout southeastern Australia. These soils are characterised by severe structural degradation that restricts root penetration, water and nutrient uptake, and crop performance. In February 2017, a field experiment was established on-farm near Rand in southern NSW to understand the amelioration p...

Alkaline dispersive subsoils are common in cropping areas of southeastern Australia, which exhibit a range of physiochemical properties including dispersion, poor structure, impeded drainage, waterlogging and high soil strength. These properties restrict the rooting depth of crops, resulting in yield penalties due to reduced extraction of water and...

Background and aims Alkaline dispersive subsoils are characterised by multiple physicochemical constraints that limit plant water and nutrient acquisition. Subsoil amelioration through organic amendments (OAs) requires significant financial investment. Whereas large yield responses can result following amelioration, sometimes small or even negative...

Highly alkaline soils are widespread throughout south‐eastern Australia. High pH limits the accumulation and retention of organic carbon (C), and thus, the availability of nutrients to crops and is also associated with various elemental deficiencies and toxicities that restricts crop productivity. Applying gypsum and increasing legume production re...

We compared Support Vector Machine (SVM) and Random Forest (RF) machine learning approaches with the widely used Jarvis-type phenomenological model for predicting stomatal conductance (gs) in wheat (Triticum aestivum L.) using historical measurements collected in the Australian Grains Free-Air CO2 Enrichment (AGFACE) facility. The machine learning-...

Photosynthetic stimulation by elevated [CO2 ] (e[CO2 ]) may be limited by the capacity of sink organs to use photosynthates. In many legumes, N2 -fixing symbionts in root nodules provide an additional sink, so that legumes may be better able to profit from e[CO2 ]. However, drought not only constrains photosynthesis but also size and activity of si...

Elevated atmospheric CO2 concentration (e[CO2]) stimulates biomass and yield of crops through the 'CO2 fertilisation effect'. Stimulation of biomass with supplemental nitrogen (N) under e[CO2] may influence water use dynamics, which is particularly important in relatively low yielding dryland Mediterranean regions where timing of water limitations...

Elevated CO2 (e[CO2]) can stimulate N2 fixation of legumes via increases in photosynthetic carbon supply to symbionts. N2 fixation mechanisms are highly sensitive to drought but little is known about changes in nodule metabolism under e[CO2] and water restriction. To address these challenges, N2 fixation and changes of carbohydrate and nitrogen met...

Dispersive sodic soils are common in the cropping areas of southeastern Australia and due to their poor water infiltration rate, transient waterlogging may occur, even following a small rainfall event. Transient waterlogging causes significant changes to soil chemistry that can severely reduce root growth and result in yield loss. To date there is...

A series of field and incubation experiments were conducted to address the amelioration process of physicochemical constraints of alkaline sodic dispersive subsoils. A range of organic and inorganic amendments were applied in the top and subsoils with the plots sown to barley and wheat in 2017 and 2018, respectively. The initial results indicated t...

The stimulatory effect of elevated [CO2] (e[CO2]) on crop production in future climates is likely to be cancelled out by predicted increases in average temperatures. This effect may become stronger through more frequent and severe heat waves, which are predicted to increase in most climate change scenarios. Whilst the growth and yield response of s...

Legumes grown in Mediterranean environments frequently experience terminal drought which reduces yield and N2 fixation processes. Decreased N2 fixation during reproductive phases may constrain seed nitrogen concentrations ([N]), reducing protein concentration of grain legumes. Plants grown under elevated atmospheric CO2 concentrations ([CO2]) have...

Background and aims Increasing atmospheric carbon dioxide concentration ([CO2]) stimulates the leaf-level (intrinsic) water use efficiency (iWUE), which may mitigate the adverse effects of drought by lowering water use in plants. This study investigated the interactive effect of [CO2] and soil type on growth, yield and water use of canola (Brassica...

Background and aims Legume N2 fixation is highly sensitive to drought. Elevated [CO2] (e[CO2]) decreases stomatal conductance (gs) and improves water use efficiency (WUE), which may result in soil water conservation and allow N2 fixation to continue longer under drought. Using a Free-Air CO2 Enrichment (FACE) approach, this study aimed to elucidate...

Stimulation of grain yield under elevated [CO 2 ] grown plants is often associated with the deterioration of grain quality. This effect may be further complicated by the frequent occurrence of drought, as predicted in most of the climate change scenarios. Lentil (Lens culinaris Medik.) and faba bean (Vicia faba L.) were grown in the Australian Grai...

The ‘CO2 fertilisation effect’ is often predicted to be greater under drier than wetter conditions, mainly due to hypothesised early season water savings under elevated [CO2] (e[CO2]). However, water savings largely depend on the balance between CO2-induced improvement of leaf-level water use efficiency and CO2-stimulation of transpiring leaf area....

This study investigated crop water use of wheat grown in a dryland Mediterranean-type environment under elevated atmospheric CO2 concentrations ([CO2]). Two related cultivars, contrasting in agronomic features (cvs. Scout and Yitpi; Scout has good early vigour and high transpiration efficiency), were grown under ambient [CO2] (a[CO2], ∼400 μmol mol...

This study investigated the interactive effects of atmospheric CO⁠2 concentration ([CO⁠2]) and water availability on yield, root growth and water use of two canola cultivars with contrasting growth and vigour (vigorous hybrid cv. Hyola 50 and non-hybrid cv. Thumper). Plants were grown under ambient [CO⁠2] (a[CO⁠2], ∼400 μmol mol⁠−1) or elevated [CO...

Through stimulation of root growth, increasing atmospheric CO2 concentration ([CO2]) may facilitate access of crops to sub-soil water, which could potentially prolong physiological activity in dryland environments, particularly because crops are more water use efficient under elevated [CO2] (e[CO2]). This study investigated the effect of drought in...

P-values of multiple comparisons (post-hoc Tukey´s HSD test) of growth and yield parameters of wheat at maturity among CO2 (a[CO2] and e[CO2]) and water treatments (WW, WD, DW and DD). (DOCX)

P-values of multiple comparisons (post-hoc Tukey´s HSD test) of above- and belowground biomass (sum of top and bottom root dry weight) of wheat at anthesis among CO2 (a[CO2] and e[CO2]) and water treatments (WW, WD, DW and DD). (DOCX)

P-values of multiple comparisons (post-hoc Tukey´s HSD test) of leaf gas exchange parameters among CO2 (a[CO2] and e[CO2]) and water treatments (WW, WD, DW and DD). (DOCX)

Increased biomass and yield of plants grown under elevated [CO2] (e [CO2]) often corresponds to decreased grain N concentration ([N]), diminishing nutritional quality of crops. Legumes through their symbiotic N2‐fixation may be better able to maintain biomass [N] and grain [N] under e [CO2], provided N2‐fixation is stimulated by e [CO2] in line wit...

This study investigated crop water use of wheat grown in a dryland Mediterranean-type environment under elevated atmospheric CO2 concentrations ([CO2]). Two related cultivars, contrasting in agronomic features (cvs. Scout and Yitpi; Scout has good early vigour and high transpiration efficiency), were grown under ambient [CO2] (a[CO2], ∼400 μmol mol...

Rising atmospheric CO2 concentration ([CO2]) stimulates plant growth and yields but lowers grain nitrogen concentration ([N]), raising concerns about grain quality in cereals. In theory, legumes can avoid such N reductions through biological nitrogen (N2) fixation. This was confirmed for studies conducted in high rainfall agro-ecosystems suggested...

Elevated [CO2] (e[CO2]) has profound effects on biomass, yield and water use of crops. At least in C3 crops, e[CO2] stimulates the photosynthetic rate (Anet) and decreases stomatal conductance (gs). Consequently the intrinsic water use efficiency (ITE) increases. Greater ITE may conserve soil water for longer, making water reserves available later...

Increasing atmospheric CO2 concentration ([CO2]) has profound effects on plant growth, yield and water use. Elevated atmospheric [CO2] (e[CO2]) increases above-and below ground biomass production of wheat. The increased root growth under e[CO2] may allow the extraction of subsoil water, which is especially important in hot and dry Mediterranean con...

The rise in atmospheric CO2 concentration from 400 to 550 ppm by 2050 will stimulate crop growth and yield and legumes may have a competitive advantage over non-legumes due to stimulation of N2 fixation under elevated CO2. However, heat stress is a major limitation to crop yield and elevated CO2 may mitigate the effects of heat shock impacts. This...

Optimising water use is a central element of maintaining crop growth and yield in less favourable, drier climates. Rising CO2 levels alter responses of plants. Some of these responses can be used to help mitigate the effect of rising temperature, less frequent precipitation and prolonged drought. We speculate that closure of stomata under elevated...

Atmospheric CO2 ([CO2]) has been increasing since the industrial revolution and is predicted to rise from currently ~400 to ~550 ppm by 2050. This rapid increase in [CO2] enhances plant growth and yield but decreases stomatal conductance (gs), leading to enhanced crop water use efficiency. Crop responses to elevated [CO2] (eCO2) in dry-land Medite...

Water limitation may prove to be a critical constraint to crop growth. Mungbean is most susceptible in that respects neither tolerate deficiency nor the excess moisture. Therefore, the present experiment was conducted to assess water stress consequence on the morpho-physiological attributes of mungbean (Vigna radiata L.) cv. BINA mung 5 in Agronomy...

Nitrogen and potassium are the yield-limiting nutrients in rice production regions of Bangladesh. Use of efficient N and K dose is an important complementary strategy in improving rice yield and quality and reducing cost of production. In order to assess the influence of nitrogen and potassium on the yield response of NERICA 1 rice in Aus season, a...

Water limitation may prove to be a critical constraint to crop growth. Mungbean is most susceptible in that respects neither tolerate deficiency nor the excess moisture. Therefore, the present experiment was conducted to assess water stress consequence on the morpho-physiological attributes of mungbean (Vigna radiata L.) cv. BINA mung 5 in Agronomy...

Higher grain yield (2.45 t ha -1) was obtained in BRRI dhan34 than that of Kalizira (2.23 t ha -1). Fertilizer application @ 1.8g USG and other inorganic fertilizer (full dose for T. aman + PM at 3.5 tha -1) gave the highest grain yield (2.85 t ha -1) and lowest grain yield (1.52 t ha -1) was found at control (no PM and NPKS). Grain yields were aff...