Rainfed Areas Research Articles

Evaluation of Wild Almond Genotypes Grown as a Rain-fed Crop in Sulaimani Governorate using RAPD and ISSR Markers

Almond is considered the most common and essential nut grown in the rainfed area. It has many species wildly distributed in the Iraqi Kurdistan region, which are called Chaqala by local people. To understand and improve the characteristics of the cultivated almonds, a comprehensive study of wild almonds in terms of population structure and genetic diversity is needed to transfer new traits into the domesticated almonds. So, twelve different genotypes were collected and analyzed using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. The results revealed polymorphic bands for both markers, the mean value of 5.8 for the RAPD marker and 7.8 for the ISSR marker was also documented. The polymorphic information content (PIC) values were obtained for RAPD primes that range between (0.64-0.85) and ISSR primers were also verified between (0.53-0.91), which shows the discriminatory power of these markers. “Jaccard similarity coefficients” were obtained between 0.34 (G11 vs. G12) to 0.77 (G1 vs. G10), and clustered into four groups with a mean similarity (0.65) for ten RADP markers. For ten ISSR markers, 0.35 (G8, G10) to 0.79 (G6 vs. G11) were also observed, which is clustered into a mean similarity (0.65). Structure analysis of RAPD and ISSR showed two major groups. Overall, these outcomes showed the diversity between the studied genotypes and among groups which are highly important for future almond breeding and conservation programs.

Climate change effects on soil salinity in rainfed maize areas: a case study from South Africa

Abstract In maize fields, few studies have been conducted to identify the temporal trend of soil salinity and formulate optimal irrigation plans under climate change. Therefore, the main goals of this study were to predict changes in soil salinity over 2022–2050 and to formulate an optimal supplemental irrigation plan preventing soil salinity in a South African rainfed maize field. The study used the Global Climate Model (GCM) MPI-ESM1-2-LR to obtain future climate data for the study area from 2022 to 2050 and applied the HYDRUS-1D model to project the effects of these future climate data on soil salinity over the same period and to identify the best irrigation plan under climate change. Two key findings were revealed: first, the combined use of GCMs (i.e., MPI-ESM1-2-LR model) and soil-water models (i.e., HYDRUS-1D) was a powerful tool to identify soil salinity trends and formulate optimal irrigation plan under climate change. Second, in addition to rainfall amount, supplying a limited supplemental irrigation amount equal to 8% of the actual evapotranspiration of maize at the mid-season stage of maize growth can significantly reduce soil salinity (<1.7 dS m−1) and enhance soil moisture under climate change by 2050. These findings will be useful for preventing soil salinity in rainfed maize fields.

Evaluation of wheat (Triticum aestivum L.) lines for drought tolerance in Kyrgyzstan

The study was carried out to explore drought stress indices in F4 hybrid generations of Triticum aestivum L. to select drought stress tolerant lines for rainfed areas of Kyrgyzstan. Wheat is the main food crop in Kyrgyzstan. There are about 0.3 million ha allotted for wheat, more than half of these sown areas (0.2 million ha) are in rainfed farming zones, where the amount of precipitation rarely exceeds 300-400 mm per year. The study was conducted in 2019 at the experimental field of Agricultural Faculty of Kyrgyz-Turkish Manas University. Eighteen hybrid lines of spring wheat and two released varieties (standard) were evaluated under irrigated and non-irrigated conditions. The results of the study show that the mean grain yield of evaluated lines under stress condition as compared to non-stressed condition was decreased by 51.72%. The analysis of correlation coefficient indicated that the productivity of lines under both conditions highly depends from their stress tolerance indexes (STI) (0.769 to 0.928). Tolerance index (TOL) and stress susceptibility index (STI) were negatively correlated (-0.411 to -0.813) with yield of genotypes under stress condition (YS). The correlation between yield stability index (YSI) and yield of genotypes under stress condition (YS) was strongly and highly positive (1.000). Based on provided analysis, Line-1, Line-3, Line-5, Line-12, Line-13, Line-14 and Line-15 were selected as potential genotypes to cultivate in drought areas of Kyrgyzstan and can be used as drought tolerance genetic resources in crop improvement programs. Keywords: Correlation; Drought tolerance; Hybrid lines; Stress tolerance indices; Triticum aestivum L.

Regulation of soil water and nitrate by optimizing nitrogen fertilization and the addition of manure based on precipitation: An 8-year field record

Optimizing fertilization strategies to improve water utilization efficiency and obtain higher crop yields and low nitrate leaching is essential for balancing food security and environmental risks in the rain-fed area of the Loess Plateau. The eight consecutive years (2014–2022) field experiment followed a split-plot design, and the experimental factors were nitrogen application rate (N0, N75, N150, N225, and N300) and manure application rate (M0 and M1). In general, (1) the relationships between nitrogen application rate and grain yield (GY), crop N uptake and water utilization efficiency (WUE) followed a quadratic curve. Compared with chemical fertilizer alone (NPK), chemical fertilizer plus manure (MNPK) significantly increased the annual average grain yield by 28.5%, 18.3%, 8.9%, 6.9% and 4.2% at the N application rate of N0, N75, N150, N225 and N300. (2) The nitrate accumulation (SNA) in the same soil layer increased with the nitrogen application rate. The residue nitrate will increase dramatically when the N application rate exceeds 150 kg ha-1. The peaks of SNA gradually moved to the deeper layer with increasing years of fertilization. The total soil nitrate accumulation (TSNA) of NPK was significantly higher than that of MNPK in dry and normal years, but the opposite was true in wet years. The total soil water storage (TSWS) decreased and then increased with the N application rate, and the annual average TSWS of the MNPK treatments was 3.9% less than that of the NPK treatments. (3) The addition of manure significantly increased the annual average moisture storage rate (MSR) during the fallow season by 4.6%. The GY in dry and normal years was more dependent on MSR than that in wet years. In terms of the long-term effects, the MSR contributes more to GY than growing season precipitation (GSP), and the high MSR caused by manure application reduced TSNA and TSWS by promoting crop growth. The results showed that M1N150 could obtain a high grain yield while maintaining low nitrate residue. Taken together, this study emphasized the importance of optimizing nitrogen fertilizer management and cattle manure application in combination with precipitation types to ensure food production and reduce negative environmental effects in the rain-fed area of the Loess Plateau in China.

Soil respiration in response to biotic and abiotic factors under different mulching measures on rain-fed farmland

Mulching measures strongly affect the soil physicochemical properties and crop growth. However, the effects of crop growth and the soil environment under mulching on soil respiration (Rs) and its components (Rh: heterotrophic respiration; Ra: autotrophic respiration) are still unclear. Therefore, in this study, we conducted an experiment in a maize field for five consecutive years with different mulching measures in a rain-fed area of China (P: flat planting with full plastic film mulching; R: ridge–furrow with half plastic film mulching; S: flat planting with full straw mulching; and CK: conventional tillage without mulching). The changes in the Rs, Rh, Ra, soil physicochemical properties, and microbial communities were monitored. The results showed that compared with CK, Rs increased by 37.4% under P, 20.3% under R, and 24.6% under S, and Rh and Ra increased by 768–1257 kg C ha–1 year–1 and 278–678 kg C ha–1 year–1, respectively. Among all of the treatments, the largest increases in the soil respiration emission fluxes and their components occurred under P. Plastic film mulching (P and R) significantly increased the aboveground biomass, leaf area index (LAI), root biomass, and grain yield in maize, whereas S had different effects on maize growth in different years. In addition, mulching significantly changed the soil physicochemical properties comprising the soil temperature, soil water content, NO3–, dissolved organic carbon, and microbial biomass carbon. Structural equation modeling showed that these physicochemical properties explained 89% of the variability in Ra and 71% of the variability in Rh. In addition, the changes in the Rs, Rh, and Ra rates were influenced by the soil bacterial diversity (Shannon diversity) and relative abundances of certain bacterial community members (Proteobacteria, Acidobacteria, Actinobacteria, Gemmatimonadetes, and Firmicutes). In summary, our results demonstrate that the Rs components were strongly influenced by SWC, ST, NO3–, and the soil microbial community. In particular, the increased soil carbon emissions under mulching were mainly due to Rh, and Rh was highly sensitive to the changes in precipitation. P obtained the highest soil carbon emissions and maize yield among all treatments, whereas S had a poor effect on increasing the yield. Considering climate warming and food security issues, R performed best.

Screening of rice (Oryza sativa L.) genotypes for root characters related to drought tolerance and its association with yield under aerobiccondition

problem in major rice growing areas where there is acute scarcity of water and in rainfed areas where cultivation depends on the seasonal rainfall. So, in order to overcome the scarcity of water for rice cultivation, breeders have made prompt efforts to breed the genotypes which can tolerate the drought stress condition. So, to develop such an efficient breeding programme, selecting the plants with desirable root characters is one of the major objectives that enables plants to withstand stress condition. Hence, the present investigation was carried under aerobic condition to evaluate 21 aerobic genotypes released by recognized agricultural institutes/universities for drought tolerance whose potentiality conferred by root traits and also correlation studies with grain yield by taking field trial involving the same genotypes. The root studies can be done in PVC pipes as well as in polythene bags. Eight genotypes viz., MAS-26, MAS -946-1, CR DHAN-204, CR DHAN- 206, CR DHAN-210, DRR DHAN-41, DRR DHAN 54, DRR DHAN-55 and one check variety Belgaum Basmati showed significantly superior mean values for most of root traits. The grain yield had positive significant association with root length, root volume, root/shoot ratio and root number indicating the perfect criteria for selection for genetic improvement for drought tolerance. Therefore, for efficient breeding programme suitable for drought tolerance these genotypes can be potential donors in drought resistance breeding programme. &nbsp

Impact of organic and integrated production systems on yield and seed quality of rainfed crops and on soil properties.

Mineral and vitamin deficiencies together affect a greater number of human populations in the world than does protein malnutrition. Organic farming is reported to improve nutritional quality of food grains while also improving soil health. However, sufficient scientific information on several aspects of organic farming based on long-term studies is lacking particularly under rainfed conditions of India. The purpose of this study was to assess the long-term impact of organic and integrated production systems on crops yield and quality, economic returns and soil properties. The study was conducted with three crops, sunflower (Helianthus annuus L.), pigeonpea (Cajanus cajan L.), and greengram [Vigna radiata (L.) Wilczek] under three different production systems, control (use of chemical inputs alone), organic and integrated. The results of the 10-year study revealed that, the average production of integrated system was on par with organic management and recorded significantly higher pigeonpea equivalent yield (PEY) (827 kg ha-1) compared to control (chemical inputs) (748 kg ha-1). In general, the yield gap between organic and integrated production systems declined from fourth year for greengram and eighth year for sunflower, during the 10-year experimental period whereas the pigeonpea yield was similar under both production systems from first year. Plots under organic management had significantly lower bulk density (1.18 mg m-3), higher water holding capacity (38.72%) and porosity (53.79%) compared to integrated production system and control (chemical inputs). The soil organic C (SOC) content in the plots under organic production system was 32.6% more than the initial organic carbon of the soil (0.43%), with higher soil N (205.2 kg ha-1). Plots under integrated production system, however, had higher soil P (26.5 kg ha-1) compared with other treatments. The dehydrogenase activity (5.86 μg TPF g-1 soil h-1) and microbial biomass carbon (317.3 μg g-1 soil) content was higher in the plots under organic production system than under other systems. Organically produced pigeonpea and greengram seeds had similar protein content with that of integrated system, and higher K and micronutrient (Fe, Zn, Cu, and Mn) contents than other treatments. The results show the potential of organic production system in improving crop yields, soil properties and produce quality in semiarid rainfed areas.

Kombinasi Pemupukan Organik dan Anorganik Terhadap Laju Pertumbuhan dan Rasio Bobot Basah Tajuk Akar Tanaman Padi Sawah (Oryza sativa L.)

Rice as one of the main food sources for the Indonesian people, especially North Sumatra, is still not able to meet the needs even though it has large land potential, so it is necessary to increase production through fertilization. This study aims to determine the effect of a combination of organic and inorganic fertilization on the growth of paddy rice plants. This study used a factorial randomized block design consisting of three factors, namely KCL (K) at 4 dose levels, namely K0 (0 kg/ha), K1 (25 kg/ha), K2 (50 kg/ha) and K3 (75 kg/ha). ), Urea (U) two levels namely U1(250 kg/ha) and U2 (225 kg/ha), Straw Compost (J) 2 levels namely J0 (0 tons/ha) and J1 (5 tons/ha) with a total The treatment combinations were 16 and consisted of 3 replications and 48 samples. Held in the rain-fed rice field area of Clove Turi sub-district, Binjai City. Soil sample analysis was carried out at the Analytical Laboratory of PT. Socfin Indonesia (SOCFINDO), Medan City and the Research and Technology Laboratory, Faculty of Agriculture, University of North Sumatra. The combination of inorganic and organic fertilizer treatments consisting of Potassium, Urea and Straw Compost showed no significant effect on the observed parameters of plant growth rate (cm/week) and root canopy wet weight ratio (grams). The highest plant growth rate was shown by the interaction of the three treatments, namely K3U2J0 of 10.33 cm/week, while the lowest data was shown by the interaction of the three treatments, namely K1U2J0 of 8.87 cm/week. The highest root canopy wet weight ratio was shown by the interaction of the three treatments, namely K1U1J0 of 8.69 grams while the lowest data was shown by the interaction of the two treatments between potassium and straw compost, namely K2J0 of 5.01 grams.Keywords: Fertilizer; Organic; Inorganic; Growth; Paddy

Quinoa plant architecture: A key factor determining plant productivity and seed quality under long-term drought

Chenopodium quinoa (quinoa) is an underutilized crop proposed as key to achieving food security within the current climatic context, where water scarcity in rainfed areas is becoming more frequent and severe, especially in Mediterranean regions. Thus, aiming at deepening our knowledge regarding the impact of water limitation on the quinoa seed nutritional quality, seeds obtained from primary and secondary panicles of four different European-adapted cultivars (F14, F15, F16, and Titicaca) growing under full irrigation and water-limiting conditions, were here analyzed. A set of parameters were evaluated in this work, including agronomical (such as yield, seed weight, seed area, and seed germination and viability rates) and nutritional (including the seed proximate composition, mineral content, and antioxidants) traits. Our results indicate that the morphological changes associated with drought stress affect secondary panicles’ seed yield. This phenomenon was generally associated with an improvement in the nutritional quality of those seeds. However, cultivars such as F16, despite keeping total seed yield under low water availability, showed drought's detrimental effect on the seed nutritional quality. In contrast, cultivars like F15 and Titicaca reduced their seed yield under water-limiting conditions but increased their protein, iron, copper, calcium, manganese, and zinc contents, especially in secondary panicles. Therefore, the dichotomy between seed quantity and quality has to be considered in this crop under water stress scenarios, highlighting differences in sink strength along the plant panicles determining seed nutritional quality.

Simultaneous improvement and genetic dissection of drought and submergence tolerances in rice (Oryza sativa L.) by selective introgression.

Drought and submergence are contrasting abiotic stresses that often occur in the same rice crop season and cause complete crop failure in many rain-fed lowland areas of Asia. To develop rice varieties with good tolerances to drought and submergence, 260 introgression lines (ILs) selected for drought tolerance (DT) from nine BC2 populations were screened for submergence tolerance (ST), resulting in 124 ILs with significantly improved ST. Genetic characterization of the 260 ILs with DNA markers identified 59 DT quantitative trait loci (QTLs) and 68 ST QTLs with an average 55% of the identified QTLs associated with both DT and ST. Approximately 50% of the DT QTLs showed 'epigenetic' segregation with very high donor introgression and/or loss of heterozygosity (LOH). Detailed comparison of the ST QTLs identified in ILs selected only for ST with ST QTLs detected in the DT-ST selected ILs of the same populations revealed three groups of QTLs underlying the relationship between DT and ST in rice: a) QTLs with pleiotropic effects on both DT and ST; b) QTLs with opposite effects on DT and ST; and c) QTLs with independent effects on DT and ST. Combined evidence identified most likely candidate genes for eight major QTLs affecting both DT and ST. Moreover, group b QTLs were involved in the Sub1regulated pathway that were negatively associated with most group aQTLs. These results were consistent with the current knowledge that DT and ST in rice are controlled by complex cross-talks between or among different phytohormone-mediated signaling pathways. Again, the results demonstrated that the strategy of selective introgression was powerful and efficient for simultaneous improvement and genetic dissection of multiple complex traits, including DT and ST.

Evapotranspiration of Winter Wheat in the Semi-Arid Southeastern Loess Plateau Based on Multi-Source Satellite Data

Continuous monitoring of evapotranspiration (ET) at high spatio-temporal resolutions is vital for managing agricultural water resources in arid and semi-arid regions. This study used the enhanced spatial and temporal adaptive reflectance fusion model (ESTARFM) to calculate the ET of winter wheat between the green-up and milk stages in Linfen Basin, a typical, semi-arid area of the Loess Plateau, at temporal and spatial resolutions of 30 m and 8 d, respectively. We then analyzed the impact of meteorological factors on ET and its variation during the main growth period of winter wheat. The fused ET data displayed the spatial details of the OLI ET data better and could accurately reflect ET variation and local sudden variations during the main growth period of winter wheat. Moreover, winter wheat ET in rain-fed areas is more heavily influenced by meteorological factors, and the effect is more direct. Affected by the synergistic effect of wind velocity, precipitation, and temperature, the ET of winter wheat in rain-fed area was lower in the green-up stage. Then, ET gradually increased, reaching its maximum in the heading–grain filling stage. At the jointing stage, temperature had a significant effect on ET. A combination of precipitation and temperature had the greatest impact on the ET of winter wheat in the heading–filling stage. In the milk stage, meteorological factors had a minor impact on ET. This study serves as a reference for ET in winter wheat in semi-arid areas and its influencing meteorological factors, which can assist in drought mitigation and regional food security strategies.

First report of Alternariaster helianthi causing leaf blight disease of sunflower (Helianthus annus) in Sudan

In Sudan, oilseed crops rank second in production area after cereals, and sunflower (Helianthus annuus) is considered a promising oilseed (Mohammed, 2010). Leaf blight caused by Alternariaster helianthi is a destructive disease of sunflower. During autumn 2018 and 2019 diseased sunflowers with dark brown to black leaves and stem spots were observed in the Blue Nile state, Sudan. The disease incidence in the major rain-fed areas, approximately 690 hectares, was 90 and 88% in 2018 and 2019, respectively. Symptoms on the leaf surface were observed most frequently after flowering. The disease appeared in the form of small scattered brown spots on the leaf lamina. Leaf spots were irregular, circular and 5–10 mm in diameter. Later these spots increased in size and coalesced covering a larger leaf area, with a dark brown margin and yellow halo. Necrotic lesions also appeared on the stem, petioles and sepals (Figs. 1, 2) with spots on younger plants exhibiting a yellow halo (Fig. 3). Infected leaf and stem tissues were surface-sterilised with sodium hypochlorite (1% v/v) for three minutes, then rinsed three times with distilled water and plated on potato dextrose agar. The plated tissue produced dark olivaceous to black colonies after five to seven days. The conidia were solitary, non-beaked, borne on simple unbranched conidiophores, cylindrical to elongate and elliptic (Fig. 4). The conidium colour was subhyaline to very dilute tan, becoming slightly darker in the most mature conidia, the conidia were variable in size from 18.1 to 23.9 μm wide and 86 to 112 μm long, and borne singly on the conidiophores. Based on the conidia and conidiophore morphology as described by Simmons (2007), the pathogen was identified as Alternariaster helianthi. For molecular identification, DNA was extracted from a representative isolate (designated AHE-2) using a DNeasy Plant Mini Kit (Qiagen, USA). PCR using a species-specific primer pair AhN1F/AhN1R (Udayashankar et al., 2012) amplified a 314 bp product which was sequenced for confirmation of A. helianthi. The resulting sequence was deposited in GenBank (Accession No. OM618612). BLASTn analysis showed that the sequence had 99% (289/291 bp) identity with an rDNA ITS sequence previously identified as A. helianthi (MK968068). Pathogenicity was determined by inoculating 30 sunflower seedlings (30 days old). Conidia from a one-week-old culture was applied to the seedlings using a 10 ml of suspension containing 106 conidia/ml. Twenty control plants were sprayed with sterile distilled water using a hand atomiser sprayer. Inoculated and control plants were covered with plastic bags and maintained in greenhouse for 24 hours after inoculation. Symptoms similar to those observed in the field appeared on all 30 inoculated plants after a few days, the percentage leaf coverage with symptoms was 38%. Alternariaster helianthi was re-isolated from the symptomatic plants, the re-isolated culture and spores were similar in morphology to the inoculated isolate. No symptoms were observed in the control plants. To our knowledge, this is the first report of A. helianthi in Sudan. Alternariaster helianthi has been reported in Uganda, Kenya, and South Africa (Kgatle et al., 2018; 2019). In this study, high disease incidences were observed, and significant yield losses may occur (Calvet et al., 2005), therefore, management strategies are needed to help prevent further spread.

Crop and livestock productivity, soil health improvement and insect dynamics: Impact of different fodder-based cropping systems in a rainfed region of India

CONTEXTFarmers in rainfed areas of South Asia depend on livestock to augment income, and provide manure for soil and crops. However, the full potential of the livestock is not realized due to the non-availability of quality fodder. The deficit may be attributed to limitation in expansion of cultivable land as well as non-availability of fodder from the protected forest areas. It is possible to enhance the productivity of the livestock by crop-livestock systems. OBJECTIVESThis study was conducted to determine the crop and fodder production potential, nutritive value of the fodder, and reductions in soil nutrients loss and pests of the seven fodder-based inter-cropping systems in a rainfed region in South India. METHODSA medium-term field experiment was conducted from 2015 to 2021 at the Gungal Research Farm of ICAR's Central Research Institute for Dryland Agriculture (17o05’ N, 78o39’E) with seven fodder-based cropping systems involving conventional crops either alone or in combinations with annual or perennial fodder species. The seven systems (treatments) were: sorghum + pigeon pea - hedge lucerne, sorghum + pigeonpea - guinea grass, castor - hedge lucerne, castor - guinea grass, sorghum - fodder - clusterbean - fodder-cowpea - fodder -horsegram, sole sorghum, and sole pigeonpea. Impacts of these systems on crop and livestock productivity, reductions in surface soil erosion and nutrient loss, and soil health and pest dynamics were studied. Livestock based studies were also conducted with the harvested fodders. RESULTS AND CONCLUSIONSWe found that sorghum + pigeonpea-hedge lucerne on average can produce 3865 kg ha−1 of sorghum grain equivalent yield and 37,820 kg ha−1 of sorghum fodder equivalent yield. The sorghum + pigeon pea-guinea grass would benefit the farmers with no animals, by selling the high biomass grass fodder and minimizing the risk of crop failure. These two systems are also better in providing green fodder for at least 8–9 months without any supplementary irrigation. We also observed increase in soil N, OC and soil microbes. There was reduction in runoff (by 51–52%) and sediment loss (by 52%), and reduced pest and disease incidence in these systems. SIGNIFICANCEOur study demonstrated that perennial fodder-based cropping systems are an excellent option to enhance the sustainability and livelihood security of rainfed farmers by reducing the risk of crop failure and supporting the livestock. These systems also open up the scope of integrating tree fodders especially in the bunds and farm borders.

Regulation of Density and Fertilization on Crude Protein Synthesis in Forage Maize in a Semiarid Rain-Fed Area

Density and fertilization mode are the key factors regulating crude protein synthesis in forage maize; however, there is a lack of systematic understanding of the regulation mechanism. Here, the nitrogen/potassium ratio (N/K), free amino acid (AA) content, crude protein synthesis key enzyme activities (nitrate reductase (NR), glutamine synthetase (GS) and glutamic pyruvic transaminase (GPT)) and crude protein content and yield in leaves, stems, and grain of forage maize, as well as the relationships among them, were explored. The results showed that the N/K of DL-40 (60,000 plants per ha−1, 40% N topdressing at large trumpet stage) and DH-50 (75,000 plants per ha−1, 50% N topdressing at large trumpet stage) significantly increased in leaves, stems, and grain, and correspondingly, NR, GS, and GPT activities in leaves, NR activities in stems, NR and GPT activities in grain, and delayed the decline in AA content. After tasseling, for DL-40 and DH-50 the crude protein content increased by 74.1% and 39.8% in leaves, respectively, 19.9% and 25.6% in grain, respectively, and crude protein yield increased by 16.7% and 35.2% in leaves, respectively, and 23.5% and 25.9% in grain, respectively. There were significant quadratic parabolic relationships of NR, GS, and GPT activities with proportion of topdressing. There was a significant relationship of crude protein content with NR activity in leaves, with NR, GS, and GPT activities in stems and with GPT activity in grain. Regulating the key enzyme activity by adjusting the density and fertilization can significantly improve the crude protein yield of forage maize. Treatments DL-40 and DH-50 significantly increased crude protein content and yield by increasing plant N/K, NR activity in leaves, NR activity in stems, and GPT activity in grain, but slowed the decrease in AA content in leaves, stems, and grain.

Yield Potential Of Indonesian Jatropha New Variety (Jet-1 Agribun) Under Rainfed Condition

Jet-1 Agribun is one of the Indonesian Jatropha new varieties suitable for rainfed areas with a high yield of dry seed and oil content. The field trial was conducted at Asembagus Experimental Station in Situbondo, East Java from February to December 2019 and aimed to observe the potential of Jatropha Jet-1 Agribun under rainfed conditions. Observation on seed yield and growth components of Jatropha plantation was also made in two and three years old Jet-1 Agribun. Results of the observation showed that Jet-1 Agribun in the first year produced seed 471.8 kg/ha. A two-year-old plant produced a dry seed of 3,958.7 kg/ha. Three-year-old plants after pruning produced dry seed 910.95 kg/ha and 916.04 kg/ha at 1 m x 1 m and 2 m x 2 m, respectively, indicating that wider spacing is more allowable for cropping with food crops until the canopy closes. Development of Jatropha should be integrated with food crops or other crops through intercropping systems, by using the land around the plants until the canopy closes.

PHYSICO-CHEMICAL ASSESSMENT OF RICE SOILS IN QUIRINO PROVINCE, PHILIPPINES

Optimum crop production is achievable with scientific soil analyses. Thus, the study was conducted in Quirino province covering rainfed and irrigated rice fields. The purpose of this study is to establish an updated database on the physical and chemical properties of these soils which intends to guide farmers in their rice farming activities, particularly on soil management. Results of the soil physicochemical analysis revealed that irrigated rice soils from Aglipay are Loam to Sandy Loam with a pH of 5.7-6.1 (medium acidic to slightly acidic) while rainfed soils are clayey with a pH of 5.3-7.1 (with strongly acidic to very slightly alkaline found to be generally). Samples collected from irrigated rice areas of Cabarroguis are majority Silty Loam with a pH of 5.8 (medium acidic), and soil samples from rainfed areas are found to be Clay Loam with a pH of 5.7 (medium acidic). On the other hand, samples gathered from irrigated areas of Diffun are dominated by Silt Loam with pH ranges from 5.4-6.3 (medium to slightly acidic); while samples from rainfed areas Clay to Clay Loam and pH of 4-5.5 (strongly acidic). Irrigated soil samples collected from Maddela are Loamy to Sandy Clay Loam with a pH ranging from 5.4-6.3 (medium to slightly acidic); while samples from rainfed were revealed to be silty Loam with a pH of 4.6 (strongly acidic). Irrigated rice soils of Nagtipunan are sandy clay with a pH 0f 6.0 (slightly acidic) while rainfed areas are found to be Clay Loam and Sandy Clay with slightly acidic to very slightly alkaline pH.With this current status of rice soils in the area, it is suitable for rice production. Furthermore, the soils assessed are also suitable for other high-value crops to avoid a monocropping system of farming.

Role of Gypsum in Conserving Soil Moisture Macronutrients Uptake and Improving Wheat Yield in the Rainfed Area

Agricultural rainfed areas of Pakistan have been facing several issues in recent years, e.g., soil erosion, nutrient runoff, and soil dependency on rainfall for crop growth. Wheat is considered a major staple crop in Pakistan. The main concern in these regions is to conserve soil moisture as the crop depends on the moisture obtained by rainfall. Gypsum is considered one of the best moisture conservers, especially for rainfed areas. Hence, this study was initiated (1) to explore the effects of gypsum on soil moisture conservation and (2) to reveal the effects of gypsum on soil macronutrients, sulfur (S), calcium (Ca), nitrogen (N), phosphorus (P), and potassium (K) uptake, and, eventually, wheat yield. The study was conducted from July 2014 to April 2015 in the rainfed Pothohar region of Pakistan. The recommended mineral fertilizers (N120P80K60) along with the following gypsum treatments: T1 = gypsum @ 0 Mg ha−1 (0 kg plot−1), T2 = gypsum @ 1 Mg ha−1 (0.6 kg plot−1), T3 = gypsum @ 3 Mg ha−1 (1.8 kg plot−1), and T4 = gypsum @ 4 Mg ha−1 (2.4 kg plot−1) were applied. The Chakwal-50 wheat variety was sown, followed by gypsum application. The maximum moisture was recorded under the soil of treatment T4 each month. The soil moisture was conserved up to 21% (surface) and 23% (sub-surface) in January and February 2015, respectively, with a 4 Mg ha−1 gypsum application. The highest nitrogen (N, 448.68 kg ha−1), phosphorus (P, 50.6 kg ha−1), potassium (K, 185.7 Kg ha−1), sulfur (S, 9.75 kg ha−1), and calcium (Ca, 35.5 kg ha−1) uptake values were observed in treatment with a 3 Mg ha−1 gypsum application (p < 0.05). The mean values of the grain yield ranged between 1903.4 (T1) and 2387.2 (T4) kg ha−1. Compared with the yield under T1, the grain yields under treatment T2, T3, and T4 were increased by 11%, 24%, and 25%, respectively. The straw yield ranged between 2446 and 2767 kg ha−1. There was no noticeable impact of gypsum application rates on the straw yield of the wheat crop (p > 0.05). Overall, treatment T3 was found to be optimal for conserving soil moisture, a better nutrient uptake, and, ultimately, the wheat crop yield with less input cost.

The Optimum Planting Time and Cropping Pattern of Potatoes and Other Horticultural Commodities based on Water Balance in Solok, Indonesia

Many mountainous regions in Indonesia have been utilized for potato cultivation. But location for the cultivation is mainly a rainfed agriculture, which greatly depend on the weather condition. Lembah Gumanti in Solok, West Sumatra is a rainfed main potato-growing area, which faced a low productivity during dry season. Therefore, efforts to optimize potato production in rainfed area remains research challenge. This study aims toidentify the optimum cropping calendar for potato and other horticultural commodities in Lembah Gumanti for 2018-2021. We used the water balance approach to derive daily water availability at field level. The approach was used to identify the planting time and pattern of potato and other horticultural commodities for 2018-2023 at dekadal (10-day) interval. The results showed that the most suitable planting time and cropping patternvaried annually. In 2018-2019, the cropping calendar was potato (in October 1st 10-day) – shallots (in April 1st 10-day) – chilies (in July 3rd 10-day). For 2020-2021, the best cropping calendar was shallots (in November 3rd 10-day) – potato (in March 3rd 10-day) – shallots (in August 1st 10-day). The findings reveal that water availability determined the cropping calendar of each commodity.

Drought tolerance of Aspergillus violaceofuscus and Bacillus licheniformis and their influence on tomato growth and potassium uptake in mica amended tropical soils under water-limiting conditions.

Drought is a significant abiotic stress that alters plant physiology and ultimately affects crop productivity. Among essential plant nutrients, potassium (K) is known to mitigate the deleterious effect of drought on plant growth. If so, K addition or inoculation of potassium solubilizing microorganisms (KSMs) that are tolerant to drought should promote plant growth during water stress. Therefore, in this study, K solubilizing Aspergillus violaceofuscus and Bacillus licheniformis, isolated from saxicolous environments, were tested for their capacity to tolerate drought using different molecular weights (~4000, 6000, and 8000 Da), and concentrations (0, 250, 500, 750, 1000, and 1250 mg/L) of polyethylene glycol (PEG) under in vitro conditions. The results showed that high concentrations (750 and 1000 mg/L) of PEG with different molecular weight considerably improved bacterial cell numbers/fungal biomass and catalase (CAT) and proline activities. Moreover, the ability of KSMs alone or in combination to impart drought tolerance and promote plant growth in the presence and absence of mica (9.3% K2O) supplementation was tested in Alfisol and Vertisol soil types under greenhouse conditions. The results revealed that the tomato plants inoculated with KSMs individually or dually with/without mica improved the physiological and morphological traits of the tomato plants under drought. Generally, tomato plants co-inoculated with KSMs and supplemented with mica were taller (2.62 and 3.38-fold) and had more leaf area (2.03 and 1.98-fold), total root length (3.26 and 8.86-fold), shoot biomass (3.87 and 3.93-fold), root biomass (9.00 and 7.24-fold), shoot K content (3.08 and 3.62-fold), root K content (3.39 and 2.03-fold), relative water content (1.51 and 1.27-fold), CAT activity (2.11 and 2.14-fold), proline content (3.41 and 3.28-fold), and total chlorophyll content (1.81 and 1.90-fold), in unsterilized Alfisol and Vertisol soil types, respectively, than uninoculated ones. Dual inoculation of the KSMs along with mica amendment, also improved the endorrhizal symbiosis of tomato plants more than their individual inoculation or application in both soil types. These findings imply that the A. violaceofuscus and B. licheniformis isolates are promising as novel bioinoculants for improving crop growth in water-stressed and rainfed areas of the tropics in the future.

The content of heavy metals in the vegetative mass of pumpkin plants when applied by the sprinkling method

Obtaining high yields of agricultural plants with their proper quality on soils contaminated with heavy metals is of the utmost importance for modern farmers of the Kuban. The purpose of the research is to study the accumulation of heavy metals in the vegetative organs of pumpkin plants, depending on the properties of the soil and the physical and chemical properties of pollutants. The tasks are to determine the influence of the physical and chemical properties of the soil on the accumulation of heavy metals in the vegetative part of the studied plants; to determine the influence of the chemical properties of heavy metals on their accumulation in the vegetative part of the studied plants. By the method of field research, the accumulation of heavy metals in the vegetative mass of pumpkin, Mramornaya variety, when applied by sprinkling method, depending on the physico-chemical properties of the soil, has been studied. Heavy metals in plants are determined by the AAS method. It has been found that when growing the studied plant on a rain-fed plot of meadow-chernozem soil, copper and cadmium accumulated in the foliage less than in the soil of rice check, respectively 2.2 and 4.9 times. The studied heavy metals had a depressing effect on the biometric parameters of the pumpkin. On the experimental plots of meadow-chernozem soil of the bogarny plot and the soil of the rice check, there was a decrease in the studied biometric parameters compared with the control. Moreover, on the meadow-chernozem soil of the rice check, this decrease was more intense. Under the influence of heavy metals and soil properties, the yield of the studied plant decreased: for the first variant it was 24.0 t/ha, for the second – 8.2 t/ha. When growing Mramornaya pumpkin variety on meadow-chernozem soil, a rain-fed area of cadmium accumulated more than copper by 16.0 times, on meadow-chernozem soil of rice check, this difference was 47.0 times. One of the reasons for this difference in the accumulation of heavy metals is their physiological role for the plant under study.