Background and aims
Subsoil acidity with a high aluminium (Al
3+
) soil content inhibits root growth and proliferation of durum wheat (tetraploid AABB,
Triticum turgidum
) leading to poor nutrient ...and water uptake. This study evaluated the impact of Al
3+
-tolerant
TaMATE1B
allele on root and shoot traits of durum wheat grown in an acidic soil with a high Al
3+
concentration.
Methods
Two durum wheat lines, Jandaroi–
TaMATE1B
with the
TaMATE1B
gene introgressed from Al
3+
-tolerant bread wheat and Jandaroi–null (a sister line lacking the Al
3+
-tolerant
TaMATE1B
allele), were grown in rhizoboxes in a glasshouse. We mapped root growth and proliferation over time and measured shoot traits and grain yield.
Results
Introgression of the Al
3+
-tolerant
TaMATE1B
allele into durum wheat enabled root growth and proliferation below 0.25 m of the soil profile, where the soil pH was low (4.1, CaCl
2
extract) with high Al
3+
content (16.5 mg kg
−1
), and increased total root length and biomass at 42 days after sowing (DAS; Z
33
) by 38.3 and 22%, respectively, relative to the Jandaroi–null. Differences in root growth between the two lines were apparent from tillering stage (Z
33
) and by 50% anthesis (Z
64
), respectively. Jandaroi–
TaMATE1B
had 69.2% greater root biomass, 76.2% greater root length, 5.89% greater leaf area and 18% greater shoot biomass than Jandaroi–null at 50% anthesis (Z
64
). Time to anthesis and physiological maturity was delayed 6–7 days in Jandaroi–
TaMATE1B
, compared to Jandaroi–null. Jandaroi–
TaMATE1B
tended to have relatively greater, but not significantly different, shoot biomass, grain yield and yield components than Jandaroi–null.
Conclusions
Introgression of the Al
3+
-tolerant
TaMATE1B
allele into durum wheat enabled root growth and proliferation down an acidic soil profile with a high Al
3+
concentration. We assume that in the field where plants need to acquire water at depth differences in above-ground parameters would be amplified.
Nitrogen (N) is an essential element required for the growth and development of all plants. On a global scale, N is agriculture's most widely used fertilizer nutrient. Studies have shown that crops ...use only 50% of the applied N effectively, while the rest is lost through various pathways to the surrounding environment. Furthermore, lost N negatively impacts the farmer's return on investment and pollutes the water, soil, and air. Therefore, enhancing nitrogen use efficiency (NUE) is critical in crop improvement programs and agronomic management systems. The major processes responsible for low N use are the volatilization, surface runoff, leaching, and denitrification of N. Improving NUE through agronomic management practices and high-throughput technologies would reduce the need for intensive N application and minimize the negative impact of N on the environment. The harmonization of agronomic, genetic, and biotechnological tools will improve the efficiency of N assimilation in crops and align agricultural systems with global needs to protect environmental functions and resources. Therefore, this review summarizes the literature on nitrogen loss, factors affecting NUE, and agronomic and genetic approaches for improving NUE in various crops and proposes a pathway to bring together agronomic and environmental needs.
Field experiments were conducted to evaluate eight different integrated crop management (ICM) modules for 5 years in a maize-wheat rotation (M
); wherein, ICM
-'business-as-usual' (conventional ...flatbed maize and wheat, ICM
-conventional raised bed (CT
) maize and wheat without residues, ICM
-conservation agriculture (CA)-based zero-till (ZT) flatbed maize and wheat with the residues, and ICM
CA-based ZT raised bed maize and wheat with the residues. Results indicated that the ICM
produced significantly (p < 0.05) the highest maize grain yield (5 years av.) which was 7.8-21.3% greater than the ICM
. However, across years, the ICM
gave a statistically similar wheat grain yield and was 8.4-11.5% greater than the ICM
. Similarly, the CA-based residue retained ICM
modules had given 9.5-14.3% (5 years av.) greater system yields in terms of maize grain equivalents (M
) over the residue removed CT-based ICM
. System water productivity (S
) was the highest with ICM
, being 10.3-17.8% higher than the ICM
. Nevertheless, the highest water use (T
) was recorded in the CT flatbed (ICM
), ~ 7% more than the raised bed and ZT planted crops with or without the residues (ICM
). Furthermore, the ICM
had produced 9.54% greater variable production costs compared to the ICM
, whereas, the ICM
gave 24.3-27.4% additional returns than the ICM
. Also, different ICM modules caused significant (p < 0.05) impacts on the soil properties, such as organic carbon (S
), microbial biomass carbon (S
), dehydrogenase (S
), alkaline phosphatase (S
), and urease (U
) activities. In 0.0-0.15 m soil profile, residue retained CA-based (ICM
) modules registered a 7.1-14.3% greater S
and 10.2-17.3% S
than the ICM
. The sustainable yield index (S
) of M
was 13.4-18.6% greater under the ICM
compared to the ICM
Hence, this study concludes that the adoption of the CA-based residue retained ICMs in the M
could sustain the crop yields, enhance farm profits, save water and improve soil properties of the north-western plans of India.
The present study is an attempt to understand the impact of bioinoculants,
Azotobacter chroococcum
(A),
Bacillus megaterium
(B),
Pseudomonas fluorescens
(P), on (a) soil and plant nutrient status, ...(b) total resident and active bacterial communities, and (c) genes and transcripts involved in nitrogen cycle, during cultivation of
Cajanus cajan
. In terms of available macro- and micro-nutrients, triple inoculation of the bioinoculants (ABP) competed well with chemical fertilizer (CF). Their ‘non-target’ effects were assessed in terms of the abundance and activity of the resident bacterial community by employing denaturing gradient gel electrophoresis (DGGE). The resident bacterial community (16S rRNA gene) was stable, while the active fraction (16S rRNA transcripts) was influenced (in terms of abundance) by the treatments. Quantification of the genes and transcripts involved in N cycle by qPCR revealed an increase in the transcripts of
nifH
in the soil treated with ABP over CF, with an enhancement of 3.36- and 1.57- fold at flowering and maturity stages of plant growth, respectively. The bioinoculants shaped the resident microflora towards a more beneficial community, which helped in increasing soil N turnover and hence, soil fertility as a whole.
Conservation agriculture (CA)-based practices have been promoted and recouped, as they hold the potential to enhance farm profits besides a consistent improvement in soil properties. A 7 years' field ...experiment consisting of three crop establishment practices viz., zero-till flatbed (ZTFB), permanent beds (PNB), conventional system (CT) along with the three-nutrient management; nutrient expert-based application (NE), recommended fertilization (RDF), and farmers' fertilizer practice (FFP), was carried out from 2013 to 2020. The CA-based practices (ZTFB/PNB) produced 13.9-17.6% greater maize grain-equivalent yield (MGEY) compared to the CT, while NE and RDF had 10.7-20% greater MGEY than the FFP. PNB and ZTFB gave 28.8% and 24% additional net returns than CT, while NE and RDF had 22.8% and 17.4% greater returns, respectively over FFP. PNB and ZTFB had 2.3-4.1% (0.0-0.20 m soil layers) lower bulk density than the CT. Furthermore, microbial biomass carbon (MBC) increased by 8-19% (0.0-0.50 m soil layers) in ZTFB/PNB over the CT, and by 7.6-11.0% in NE/RDF over FFP. Hence, CA-based crop establishment coupled with the NE or RDF could enhance the yields, farm profits, soil properties of the maize-chickpea rotation, thereby, could sustain production in the long run.
Delayed sowing of maize hybrids could exacerbate the capability of maximizing the yield potential through poor crop stand, root proliferation, nutrient uptake, and dry matter accumulation coupled ...with the inadequate partitioning of the assimilates. This study appraised the performance of five recent maize hybrids viz., PMH-1, PJHM-1, AH-4158, AH-4271, and AH-8181 under timely and late sown conditions of the irrigated semi-arid ecologies. Timely sowing had the grain and stover yields advantage of 16-19% and 12-25%, respectively over the late sown maize hybrids. The advanced hybrids AH-4271 and AH-4158 had higher grain yields than the others. During the post-anthesis period, a greater dry matter accumulation and contribution to the grain yield to the tune of 16% and 10.2%, respectively, was observed under timely sown conditions. Furthermore, the nutrient acquisition and use efficiencies also improved under the timely sown. The nutrient and dry matter remobilization varied among the hybrids with AH-4271 and PMH-1 registering greater values. The grain yield stability index (0.85) was highest with AH-4158 apart from the least yield reduction (15.2%) and stress susceptibility index (0.81), while the maximum geometric mean productivity was recorded with the AH-4271 (5.46 Mg ha
). The hybrids AH-4271 and PJHM-1 exhibited improved root morphological traits, such as root length, biomass, root length density, root volume at the V5 stage (20 days after sowing, DAS) and 50% flowering (53 DAS). It is thus evident that the timely sowing and appropriate hybrids based on stress tolerance indices resulted in greater yields and better utilization of resources.
The continuing decline in water resources under the ever-changing climate compels us to re-orient our focus to a more sustainable practice. This study investigates the performance of
wheat genotypes ...viz. HD-2967, HD-3086, HD-3249, DBW-187, and HD-3226 under well- and deficit-watered conditions for their root-traits, biomass and nitrogen accumulation and remobilization, and water use efficiencies, grown in PVC-tubes. The genotypes HD-2967, HD-3086, HD-3249, DBW-187, and HD-3226 under well-watered (WW) resulted in 36, 35, 38, 33, and 42% more grain yield compared to deficit-watered (DW). Among the genotypes, HD-3249 had the highest grain yield under both well- and deficit-watered conditions. Compared to DW, the WW had 28%, 30%, and 28% greater root length, biomass, and root length density at flowering {102 days (d), Z
}, while among the genotypes, HD-3249 had relatively greater root-traits. At flowering (Z
) and maturity (132 d, Z
), genotypes under WW accumulated 30-46% and 30-53%, respectively greater shoot biomass over the DW. Furthermore, the shoot biomass remobilised for HD-2967, HD-3086, HD-3249, DBW-187, and HD-3226 under the WW was 32, 37, 39, 35, and 35% greater than the DW. The nitrogen partitioning to different plant parts at flowering (Z
) and maturity (Z
) was significantly greater with the WW than with DW. The total nitrogen- remobilized and contribution to grain-N under the WW was 55, 58, 52, 53, 58% and 9, 19, 15, 17, 17% greater than the DW for the genotypes HD-2967, HD-3086, HD-3249, DBW-187, and HD-3226. The irrigation water use efficiency (WUE) at flowering (Z
) was more under the deficit-watered, but the biomass and grain total WUE was improved with the well-watered condition. Hence, it is apparent that proper scheduling of irrigation and N applications, along with the adoption of a genotype suited to a particular environment, will result in better WUE and grain yields, along with better utilization of scarce resources.
Sensor-based decision tools provide a quick assessment of nutritional and physiological health status of crop, thereby enhancing the crop productivity. Therefore, a 2-year field study was undertaken ...with precision nutrient and irrigation management under system of crop intensification (SCI) to understand the applicability of sensor-based decision tools in improving the physiological performance, water productivity, and seed yield of soybean crop. The experiment consisted of three irrigation regimes I
: standard flood irrigation at 50% depletion of available soil moisture (DASM) (FI), I
: sprinkler irrigation at 80% ET
(crop evapo-transpiration) (Spr 80% ET
), and I
: sprinkler irrigation at 60% ET
(Spr 60% ET
) assigned in main plots, with five precision nutrient management (PNM) practices{PNM
-SCI protocol, PNM
-RDF, recommended dose of fertilizer: basal dose incorporated (50% N, full dose of P and K), PNM
-RDF: basal dose point placement (BDP) (50% N, full dose of P and K), PNM
-75% RDF: BDP (50% N, full dose of P and K) and PNM
-50% RDF: BDP (50% N, full P and K)} assigned in sub-plots using a split-plot design with three replications. The remaining 50% N was top-dressed through SPAD assistance for all the PNM practices. Results showed that the adoption of Spr 80% ET
resulted in an increment of 25.6%, 17.6%, 35.4%, and 17.5% in net-photosynthetic rate (P
), transpiration rate (T
), stomatal conductance (G
), and intercellular CO
concentration (C
), respectively, over FI. Among PNM plots, adoption of PNM
resulted in a significant (
=0.05) improvement in photosynthetic characters like P
(15.69 µ mol CO
m
s
), T
(7.03 m mol H
O m
s-
), G
(0.175 µmol CO
mol
year
), and C
(271.7 mol H
O m
s
). Enhancement in SPAD (27% and 30%) and normalized difference vegetation index (NDVI) (42% and 52%) values were observed with nitrogen (N) top dressing through SPAD-guided nutrient management, helped enhance crop growth indices, coupled with better dry matter partitioning and interception of sunlight. Canopy temperature depression (CTD) in soybean reduced by 3.09-4.66°C due to adoption of sprinkler irrigation. Likewise, Spr 60% ETc recorded highest irrigation water productivity (1.08 kg ha
m
). However, economic water productivity (27.5 INR ha
m
) and water-use efficiency (7.6 kg ha
mm
day
) of soybean got enhanced under Spr 80% ETc over conventional cultivation. Multiple correlation and PCA showed a positive correlation between physiological, growth, and yield parameters of soybean. Concurrently, the adoption of Spr 80% ET
with PNM
recorded significantly higher grain yield (2.63 t ha
) and biological yield (8.37 t ha
) over other combinations. Thus, the performance of SCI protocols under sprinkler irrigation was found to be superior over conventional practices. Hence, integrating SCI with sensor-based precision nutrient and irrigation management could be a viable option for enhancing the crop productivity and enhance the resource-use efficiency in soybean under similar agro-ecological regions.
Zinc (Zn) ferti-fortification using different sources and methods in Zn deficient soils is being advocated to increase Zn concentration in rice kernel as an alternative to pursuing greater Zn-use ...efficiency (ZnUE). A two-year field study was conducted to assess the effect of Zn application on Zn content and uptake at several growth stages and in several parts of the rice kernel: hull, bran, and the white rice kernel. Variety ‘PB 1509’ with 1.25kgZnha−1 as Zn-EDTA+0.5% foliar spray (FS) at maximum tillering (MT) and panicle initiation (PI) stages registered the highest Zn content in hull, bran, and white rice kernel. Among parts of the rice kernel, Zn concentration decreased in the order hull>bran>white rice kernel, indicating that brown rice kernels are much denser in Zn content than polished rice. Considering the higher Zn accumulation in the bran, brown rice consumption, especially in Asia and Africa, could be recommended to overcome Zn malnutrition. The variety ‘PB 1401’ showed the highest Zn uptake in rice straw, while ‘PB 1509’ showed the highest Zn uptake in hull and white rice kernel. Application of 1.25kgZnha−1 (Zn-EDTA)+0.5% FS at MT and PI and 2.5kgZnha−1 ZnSO4·7H2O (ZnSHH)+0.5% FS at MT and PI resulted in higher Zn uptake than other treatments. On average, about one third of total Zn uptake remained in the white rice kernel, with the remaining two thirds accumulating in both hull and bran of brown rice. Zn-EDTA along with 0.5% FS, despite the application of a lower quantity of Zn leading to the highest Zn mobilization efficiency index (ZnMEI) and Zn-induced nitrogen recovery efficiency (ZniNRE), produced the highest kernel yield. However, of the two Zn sources, Zn-EDTA contributed more to the increase in ZnUE than did ZnSHH.
PDF
