Combined Effect of Poultry Manure and Soil Mulching on Soil Properties, Physiological Responses, Yields and Water-use Efficiencies of Sorghum Plants under Water Stress

Application of bio-organic amendments improves soil quality and yield of fennel (Foeniculum vulgare Mill.) plants in saline calcareous soil

The impact of bio-organic amendments on crop production is poorly understood in saline calcareous soils. The aim in the present study was to determine the effects of the application of organic manure along with lactic acid bacteria (LAB) on soil quality, and morpho-physio-biochemical responses, seed yield (SY) and essential oil yield (EOY) of fennel plants (Foeniculum vulgare Mill.) grown in saline calcareous soils. Eight treatments of farmyard manure (FM) or poultry manure (PM) individually or combined with Lactobacillus plantarum (Lp) and/or Lactococcus lactis (Ll) were applied to saline calcareous soil in two growing seasons. Either FM or PM combined with LAB had beneficial effects on lowering ECe, pH and bulk density and increasing total porosity, organic matter, and water and nutrient retention capacities in addition to total bacterial population in the soil. Growth, nutrient uptake, SY and EOY of plants were also enhanced when fennel seeds were inoculated with Lp and/or Ll and the soil was amended with any of the organic manures under unfavorable conditions. Compared to control (no bio-organic amendments), FM + Lp + Lt or PM + Lp + Lt treatment signficantlly (P ≤ 0.05) increased plant height by 86.2 or 65.0%, total chlorophyll by 73 or 50%, proline by 35 or 45%, glutathione by 100 or 138%, SY by 625 or 463% and EOY by 300 or 335%, respectively, in fennel plants. Co-application of the naturally occurring microorganisms (i.e., LAB) and organically-derived, nutrient-rich fertilizer (i.e., FM or PM) is recommended to improve yield of fennel plants in saline calcareous soils.

Phosphogypsum and poultry manure enhance diversity of soil fauna, soil fertility, and barley (Hordeum aestivum L.) grown in calcareous soils

Enrichment of calcareous soils with phosphogypsum and poultry manure amendments could increase nutrient availability, improve calcareous chemical characteristics, and enhance barley plant growth. In the current study, phosphogypsum (PG) and poultry manure (PM) were used to determine the effects of PG and PM application on soil fauna diversity, soil fertility, and barley yield. The pot experiment treatments were: C: control; PG1: 4.20 g kg^-1 soil; PG2: 6.30 g kg^-1 soil; PM1: 4.20 g kg^-1 soil; PM: 6.30 g kg^-1 soil, and their combinations. The results indicated that the application of PM alone or combined with PG had significant effects on the microbial biomass carbon (MBC), organic matter (OM), soil NPK availability, and yield of barley. Collembola and Prostigmata accounted for 50.0 and 43.3%, respectively, of the total number of soil fauna. Shannon and evenness indices increased significantly in the soil amended with PM alone or combined with PG. Amended soil with PG and/or PM significantly increased the yield and yield components of plants compared to the control. The PM1PG2 treatment increased the yield by 76.2% above the control.

The Influence of Different Crop Mulches on Weed Infestation, Soil Properties and Productivity of Wheat under Conventional and Conservation Production Systems

Pakistan and other South Asian countries rely on wheat for human nutrition. However, wheat yield is declining in the region due to several biotic and abiotic constraints. Weeds are among the major factors responsible for yield decrease and farmers manage them by intensive tillage practices. Several studies have investigated the impact of various tillage practices on weed management in wheat. However, weed suppression abilities of different mulch types are rarely tested. This three-year (2019-20, 2020-21 and 2021-22) study investigated the impact of different mulch types (prepared from different crops) on weed infestation, soil properties and productivity of wheat under conventional and conservation production systems at three locations (Multan, Hafizabad and Faisalabad) in Punjab, Pakistan. The mulches included in the study were cotton sticks mulch, mungbean straw mulch, sorghum straw mulch, rice straw mulch, sunflower straw mulch, plastic mulch, and no mulch (as control). The production systems opted for wheat cultivation were conventionally tilled wheat (CTW), zero-tilled wheat (ZTW) and zero-tilled wheat sown with happy seeder machine (HSW). The CTW resulted in the lowest soil bulk density and the highest soil porosity after wheat harvest, while ZTW behaved oppositely. Similarly, incorporation of crop mulches resulted in the highest soil porosity and the lowest soil bulk density, while no-mulch incorporation and plastic mulch recorded the highest bulk density and the lowest soil porosity. Regarding mulches by production systems' interaction, CTW with sorghum straw- and plastic mulches recorded the lowest weed density and biomass, while ZTW with no-mulch recorded the highest weed density and biomass at all locations. The CTW with mungbean straw- and plastic mulches resulted in the highest yield due to significant improvement in yield-related traits. However, ZTW with sorghum straw mulch and no-mulch resulted in the lowest wheat yield. Although sorghum straw mulch suppressed weed infestation, it negatively affected wheat growth. Economic analysis revealed that CTW with mungbean straw mulch resulted in the highest gross and net incomes and benefit:cost ratio (BCR), while the ZTW with rice straw- and sorghum straw mulches produced the lowest gross and net incomes and BCR at all locations. Therefore, mungbean straw mulch is a viable option to improve wheat productivity and net economic returns under different agro-climatic conditions of Punjab, Pakistan.

Exogenously Applied Proline Enhances Morph-Physiological Responses and Yield of Drought-Stressed Maize Plants Grown Under Different Irrigation Systems

The exogenous application of osmoprotectants [e.g., proline (Pro)] is an important approach for alleviating the adverse effects of abiotic stresses on plants. Field trials were conducted during the summers of 2017 and 2018 to determine the effects of deficit irrigation and exogenous application of Pro on the productivity, morph-physiological responses, and yield of maize grown under two irrigation systems [surface irrigation (SI) and drip irrigation (DI)]. Three deficit irrigation levels (I₁₀₀, I₈₅, and I₇₀, representing 100, 85, and 70% of crop evapotranspiration, respectively) and two concentrations of Pro (Pro₁ = 2 mM and Pro₂ = 4 mM) were used in this study. The plants exposed to drought stress showed a significant reduction in plant height, dry matter, leaf area, chlorophyll content [soil plant analysis development (SPAD)], quantum efficiency of photosystem II [Fv/Fm, Fv/F0, and performance index (PI)], water status [membrane stability index (MSI) and relative water content (RWC)], and grain yield. The DI system increased crop growth and yield and reduced the irrigation water input by 30% compared with the SI system. The growth, water status, and yield of plants significantly decreased with an increase in the water stress levels under the SI system. Under the irrigation systems tested in this study, Pro₁ and Pro₂ increased plant height by 16 and 18%, RWC by 7 and 10%, MSI by 6 and 12%, PI by 6 and 19%, chlorophyll fluorescence by 7 and 11%, relative chlorophyll content by 9 and 14%, and grain yield by 10 and 14%, respectively, compared with Pro₀ control treatment (no Pro). The interaction of Pro₂ at I₁₀₀ irrigation level in DI resulted in the highest grain yield (8.42 t ha^-1). However, under the DI or SI system, exogenously applied Pro₂ at I₈₅ irrigation level may be effective in achieving higher water productivity and yield without exerting any harmful effects on the growth or yield of maize under limited water conditions. Our results demonstrated the importance of the application of Pro as a tolerance inducer of drought stress in maize.

Consecutive seasonal effect on yield and water productivity of drip deficit irrigated sorghum in saline soils

Drought stress destructively affects the growth and productivity of sorghum crop, especially under saline soils. Therefore, Field trials were performed to determine the influence of water stress on water productivity (water productivity for grain, (G-WP) and water productivity for forage, (F-WP), yield of sorghum and soil properties in salt-affected soil (8.20 dS m⁻¹) under different sowing dates and irrigation regimes. The summer sowing (SS) was performed on 1 April while fall sowing (FS) was established on 2 August. The irrigation regimes were; 100, 90, 80, and 70% of crop evapotranspiration (ETc). The findings displayed that the fodder and grain yields were increased by 23% and 26% under SS compared to FS over the two seasons 2017 and 2018, respectively. Among irrigation levels, the maximum values of grain and fodder yield were given by 100% of ETc, while a non-significant difference was observed between 100% and 90% of ETc. Moreover, the maximum values of G-WP (1.31%) and F-WP (9.00%) were recorded for 90% of ETc. Interestingly, the soil salinity was decreased in 0–0.6 m depth, and more decline was noted in 0–0.2 m depth using 90% of ETc. The highest salt accumulation withinside the soil profile was recorded under 70% of ETc in comparison to 100% of ETc. Thereupon, under water scarcity, application of 90% of ETc is recommended with SS to save 10% of the applied irrigation water without a significant decrease in grain yield (GY).

Acidified Biochar as a Soil Amendment to Drought Stressed (Vicia faba L.) Plants: Influences on Growth and Productivity, Nutrient Status, and Water Use Efficiency

Drought is one of the major threats to global food security. Biochar use in agriculture has received much attention and improving it through chemical modification offers a potential approach for enhancing crop productivity. There is still limited knowledge on how acidified biochar influences soil properties, and consequently its influences on the agricultural productivity of drought stressed plants. The water use efficiency (I-WUE) of drought stressed faba beans was investigated through the effects of acidified biochar (ACBio) (a 3:100 (w:w) combination of citric acid and biochar) on soil properties, growth, productivity, nutrient uptake, water productivity (WP), and irrigation. Two field experiments (2016/2017 and 2017/2018) were conducted in saline soil (ECe, 7.2 dS m−1) on faba been plants grown under three irrigation regimes (i.e., 100, 80, and 60% of crop evapotranspiration (ETc)) combined with three levels of ACBio (0, 5, and 10 t ha−1). Plants exposed to water stress presented a significant decrease in plant height, dry matter, leave area, chlorophyll content (SPAD), the quantum efficiency of photosystem II (Fv/Fm, Fv/F0, and PI), water status (membrane stability index and relative water content), and seed yield. Acidified biochar soil incorporation improved soil properties (chemical and physical), plant growth, physiological responses, WP, I-WUE, and contents of N, P, K, and Ca. Results revealed that the application of ACBio at 10 t ha−1 and 5 t ha−1 significantly increased seed yield by 38.7 and 25.8%, respectively, compared to the control. Therefore, ACBio incorporation may find application in the future as a potential soil amendment for improving growth and productivity of faba bean plants under deficit irrigation.