International Journal of Plant Production
Volume:13 Issue: 3, Sep 2019

An exact experiment, established in a system of randomized blocks, was aimed at determining the efect of crop rotation and 29-year cereal monoculture on the yield and quality of winter wheat grain as well as on straw yield, crop infestation with weeds, contents of organic C and total N in the soil, and the number of earthworms in the soil. Winter wheat was sown in two systems of crop succession: (1) in crop rotation (CR), and (2) in a cereal monoculture (CM). Winter wheat cultivation in the CM system resulted in a decrease of grain yield by 32%, compared to the CR system. Its grain yield reduction in the CM system was due to a lower number of spikes m−2, lower 1000 grain weight, shorter spikes, and lower grain weight per spike, than in the CR system. Wheat grain from the CM system was characterized by a lower content of wet gluten, lesser grain uniformity and grain volume weight, and contained more total ash than the grain from the CR system. The number and air-dry weight of weeds were higher in the CM than in the CR system by 57.1% and 75%, respectively. Diferences were also demonstrated in the species composition of weeds. The soil samples collected from the CM plot contained less organic C and total N than the samples derived from the CR system. Soil samples from the CM system had also a lower number of earthworms compared to the CR soil samples.

Sowing of bacterial inoculated seeds and using different cultivar-specific row spacing are 2 well-known agricultural practices in soybean production. However, the connection between different bacterial seed inoculations and row spacing has not previously been investigated in a single study. A 3-year field experiment (2015–2017) was carried out on soybean cv. ES Mentor to assess the effect of 4 rhizobia inoculation treatments (un-inoculated control, C; factory-inoculated seed, F; fresh pre-sowing seed treatment with commercial inoculant, I; and a combination of treatments F and I, FI) and 3 row spacings (12.5 cm, 25 cm and 37.5 cm) on the protein, oil, crude fibre and ash content. The seed, protein and oil yields were determined as well as a thousand seed weight, plant height, pod number and harvest index. There was no interaction between plant spacing and inoculation; however, the inoculation treatments enhanced protein content of seeds by 1.2–1.7%, and increased yields of seed, protein and oil by a maximum of 6.8%, 8.3% and 5.9%, respectively, compared to the un-inoculated control, which produced an average seed yield of 4098 kg/ha. The inoculation treatments also had a moderate influence on biometric measurements. Row spacing had a pronounced effect on seed, protein and oil yields, with plants in 12.5 cm and 25 cm row spacings generating higher yields than those in 37.5 cm row spacings. Correlation analysis showed a significant positive association between seed yield and pod number, and a significant negative correlation between protein and oil content.

Tall and erect chickpea cultivar HC 5 (Haryana Chana 5) was primarily bred for inter-cropping with autumn planted sugarcane. Cultivar HC 5 is distinctly different in morphology from traditional bushy or semi-spreading chickpea cultivars and it is found suitable for machine harvesting. However, a general recommended planting density (30 cm × 10 cm) is being followed for cv. HC 5 as well. In this study, we hypothesized that high-density planting can improve crop productivity and also improve the plant architecture for mechanical harvesting. To test this hypothesis, four plant spacing treatments (30 cm × 10 cm, 30 cm × 7.5 cm, 22.5 cm × 10 cm, and 22.5 cm × 7.5 cm) were evaluated in two chickpea cultivars (HC 5 and JAKI 9218) for crop growth, grain yield and the desirable plant traits for mechanical harvesting. The highest grain yield of cv. HC 5 was observed with 22.5 cm × 10 cm spacing that increased the grain yield by 9% (p < 0.05) over plant spacing of 30 cm × 10 cm (conventional); this indicates that high-density planting could increase the productivity of the cv. HC 5. Where grain yield of cv. JAKI 9218 was reduced (p < 0.05) with the increase in planting density over 30 cm × 10 cm. Increased grain yield of cv. HC 5 with 22.5 cm × 10 cm spacing over 30 cm × 10 cm was mainly attributed to increase in plant density (33%); however, all the plant attributes (primary branch, secondary branch, pod plant−1) were reduced as compared to plant spacing of 30 cm × 10 cm. The decrease in intra-row spacing of cv. HC 5 resulted in a strong adverse effect on plant growth and yield parameters as compared to inter-row spacing and thus not recommended. High-density planting increased the plant height (erectness) and ground clearance of cv. HC 5 (height of first pod) (~ 30 cm), an essential prerequisite for mechanical harvesting, but not in cv. JAKI 9218. Hence, cv. HC 5 requires a dense planting for higher yield and appropriate plant structure for mechanical harvesting. Therefore, it is recommended to work out the optimum planting geometry/plant population to realize the potential yield of cultivars bred for mechanical harvesting.

Soil degradation in semi-arid regions is alarming due to changed climate impacting the rainfall patterns and temperature affecting soil physico-biological properties adversely. In India, cattle shed bedding technology (CSBT) using crop residues is cheaper, easy-to-use residue recycling method for small holders in semi-arid regions. The present research work was carried out with a specific objective of soil improvement leading to resilience of land use system using indigenously available fortified crop residue for enhanced crop and cropping system yields under both rainy and post rainy conditions in semi-arid tropics of India. Thus, a study was conducted for 2 years (2013–2014 and 2014–2015) in the farmers fields with treatments having various fortifications like bedding material with groundnut shell and its manure, compost over existing practice among farmers on rainfed groundnut-fallow (L-F), castor-groundnut (NL-L) and groundnut–groundnut (L–L) oilseed based cropping systems. These systems were evaluated for soil quality parameters, productivity, fertility, soil moisture retention, compaction, crop land utilization and economics. In different cropping systems, use of fortified groundnut shell @ 16.3–22.6 t ha−1 year−1 was able to recoup the soil nutrient losses (183.0 kg N, 6.1 kg P, 227.0 kg K and 0.3 kg OC ha−1 year−1) closely followed by compost and distantly by inorganics application with additional benefit of enhanced crop yields by 20.2–33.1% during subsequent rainy and 20.0–25.0% during post-rainy season, improved available water content (10.7–20.3%) and increased irrigation interval by 3–5 days in NL-L and L–L system. Hence, the principle of fortifying crop residues through CSBT could be utilized globally in similar agro-ecological regions for addressing soil degradation and effective crop residue utilization for small and marginal landholders farmers.

Serratia spp., strain BRM 32114, is a plant growth-promoting rhizobacteria that show strong potential to solve two major challenges of upland rice production in a no-tillage system: initial vigor and grain yield improvement. No-till practices dictate the sustainability of cropping systems as they improve precipitation use, sequester C, mitigate atmospheric CO2 enrichment, restore soil health, and stimulate interest in crop diversity and rotation design. This study was intended to analyze the effect of the Serratia spp. on growth promotion and grain yield improvement in upland rice, under four N rates. Two field experiments were conducted during growing seasons 2015/2016 and 2016/2017, in two different experimental areas managed under a no-tillage system in the Brazilian Cerrado soil. The experimental design was a complete randomized block in a 4 × 2 factorial scheme, with four replications. Treatments comprised of four N fertilizer rates (0, 40, 80 and 120 kg N ha−1) with or without BRM 32114. In BRM 32114 treatment, rice seeds were microbiolized and bacterial suspension were sprayed at soil/plant in the field on the 7th and 15th DAS (day after sowing). Morphophysiological (gas exchange, shoot nutrients content and biomass production), and agronomic (grain yield and its components) traits were estimated. Results revealed increase in stomatal conductance (~ 20%); N, Ca and Mg (7, 11 and 9%) contents; shoot dry matter (8%); number of grain per plant (17%); mass of 1000 grains (2%) and yield (~ 22%) in BRM 32114-treated rice and cultivated in soil fertilized with 0, 40 and 80 kg N ha−1. However, the efficacy of this strain was reduced when combined with the highest rate of N (120 kg ha−1) added to the soil. It is possible to get higher yields levels of upland rice, cultivated under no tillage system, with the complimentary use of Serratia sp., strain BRM 32114, than the application of chemical fertilizers alone. The improvement in soil health could be extra benefit for fertilizer’ savings.

The number of areas subject to drought is likely to increase in response to climate change and will affect the yields of globally important crops such as sugarcane. In this respect, the aim of the present study was to assess the drought tolerance of sugarcane varieties in different phenophases and identify the physiological and biochemical characteristics associated with the lowest yield loss under drought conditions. Six of the most widely cultivated varieties in the region were studied, namely SP79-1011, RB855113, RB92579, RB867515, RB72454 and RB855536. Plant physiological characteristics were assessed during the dry season in the tillering, intense growth and ripening stages, and yield was quantified after 12 months of cultivation. This study shows that different sugarcane varieties are more affected by drought in the intense growth phenophase, since plants showed a greater decline in water and osmotic potential at midday during this period. The varieties most affected by drought in this phenophase were RB855536 and RB855113, which exhibited greater reductions in water and osmotic potential. They also had larger osmoregulator accumulation as a response to drought, but not enough to prevent dehydration, which likely contributed to the lower yield. The RB867515 and RB92579 varieties underwent no significant change in osmotic potential at midday during drought stress in the intense growth phase, despite of low leaf water potential, and little variation in the osmoregulators contents. For these reasons, these two varieties showed greater drought acclimation potentials and were more productive as submitted to drought conditions.

Restoring soil fertility is essential to sustain crop production in order to meet the needs of the ever-blooming population. In this light, the present investigation was conducted on the same soil for two consecutive years (2014–2015 and 2015–2016) in Punjab, Pakistan, to determine the influence of press mud compost (PMC) and mineral fertilizers (NPK) on wheat growth, yield and soil properties. The experiment was composed of an unfertilized control and five inter-exchanging combinations of NPK and PMC (100:0, 75:25, 50:50, 25:75, 0:100). 100% PMC (900 kg ha−1) was intermediate in wheat growth and yield between unfertilized and 100% NPK, this latter being the recommended dose of mineral nutrients (120, 100 and 60 kg ha−1 of the respective N, P2O5, and K2O). The 50:50 combination of NPK and PMC determined the best growth and final yield (+ 19% vs. 100% NPK), despite an approximately 40% lower nutrient supply with respect to 100% NPK. Soil traits bulk density, pH, organic matter, total N, and available nutrients P and K significantly improved with 100% PMC. Based on the ANOVA, the 50:50 combination of NPK and PMC was no worse than 100% PMC in bulk density, available P and K, and it was a good compromise between 100% NPK and 100% PMC in organic matter content. Therefore, conjunctive use of PMC and NPK fertilizers appeared a good choice to improve wheat productivity and soil properties. Additionally, the use of PMC will lower the reliance on mineral fertilizers while restoring soil fertility and assuring environmental protection.

Accurate nitrogen (N) fertilisation increases crop yields and minimises environmental pollution in maize based production systems. In this study we report on a meta-analysis of the effects of N fertilisation on maize yield using observations from 53 studies conducted in Zimbabwe since the 1950s for possible refinement of fertiliser recommendations. We assessed the response of maize to: < 30; 30–100 and > 100 kgN ha−1 compared to the control using the weighted mean yield difference approach. Application of N fertiliser significantly (p < 0.001) increased maize yields by between 0.25 and 1.6 t ha−1 compared to control. These effect sizes increased with N rate and rainfall amount and were higher in the better managed large scale sector than the smallholder sector, but highest (1.527 t ha−1) in loamy soils (20–35% clay) and lowest (0.750 t ha−1) in the sandy soils (< 20% clay). In addition, the effect sizes where mineral N fertilisers were applied were 6.3% higher than those for mineral + organic N fertiliser application due to slow N mineralisation of organic resources. In conclusion, soil hydraulic properties and associated N transformation processes greatly influenced maize yield response calling for optimised application rates and maize growers in Zimbabwe, and similar areas in Sub-Saharan Africa, can substantially increase yields by applying > 100 kgN ha−1 (> 1.5 fold of recommended blanket rate) in mineral form in loam soils under good management in areas that receive 600–1000 mm year−1 rainfall whilst rates of < 30 kgN ha−1 (< 50% of recommended rate) can be relied upon for positive yield response in small holder areas that receive < 600 mm rainfall year−1.