Climate‐strategic agriculture and the water‐soil‐waste nexus

Adoption of input‐responsive varieties enhanced food production during the second half of the 20th century. However, even bigger challenges lie ahead because of the growing societal demands. For example, the global population of 7.2 billion in 2013 is projected to reach 9.2 billion by 2050 and stabilize at 10 billion by 2100. The growing and increasingly affluent population, with preference towards more and more meat‐based diet, is likely to jeopardize the finite, fragile, and dwindling soil and water resources which are already under great stress in densely populated countries in Asia and elsewhere. Economic growth and increase in gross domestic product also lead to generation of waste or by‐products, along with contamination and eutrophication of water resources. International trade in food/feed products also involves transfer of virtual water, which is a serious issue when water‐scarce countries export virtual water to water‐endowed countries. The problem is confounded by the present and future climate change driven by the growing energy demands of the carbon civilization. Thus, adaptation to climate change represents both a threat and an opportunity for sustainable development. Adaptive strategies must be sustainable socially and environmentally and advance the Millennium Development Goals, while buffering agroecosystems against extreme climate events (e.g., pedologic, agronomic, and ecologic drought). Thus, recognizing and addressing the water‐soil‐waste nexus is important to achieving climate‐strategic agriculture. Sustainable intensification of agroecosystems, producing more per unit consumption of essential resources, must consider judicious management of hydrological and biogeochemical cycles (C, N, P, S). The soil C pool must be managed and enhanced to offset anthropogenic emissions, and mitigate/adapt to the climate change. The pace of adoption of recommended land use and soil‐/plant‐/animal‐management practices can be kept at par with advances in scientific knowledge through continuous dialogue between scientists on the one hand and policy makers / land managers on the other to translate research data into policy and action plans.     

Plum pox virus: diagnosis and spread inhibition by weed control

Journal of Plant Diseases and Protection - Plum pox virus (PPV) is a plant virus (genus Potyvirus, family Potyviridae) infecting stone fruit trees. Since the first report from Bulgaria in 1917, PPV...     

Effect of nutrients and plant extracts on Alternaria blight of tomato caused by Alternaria Alternata

Journal of Plant Diseases and Protection - Studies with nutrients and phyto-extracts were performed in vitro and in vivo to assess their potential in controlling Alternaria blight of tomato...     

Effect of coconut palm wine (Toddy) on carbohydrate metabolism in pregnant rats and fetuses

The objective of this study was to determine the effects of an alcoholic beverage (Toddy) and the equivalent quantity of ethanol on carbohydrate metabolism in utero. Female rats were exposed to Toddy from coconut palm (24.5 ml/kg body weight/day) and ethanol (0.52 ml/kg body weight/day) for 15 days before conception and throughout gestation. On the 19th day of gestation, hypoglycemia was seen in both the treated groups, but it was more in the Toddy-treated group. Synthesis of glycogen was elevated on exposure to ethanol/Toddy but its degradation was enhanced only in alcohol-exposed rats. Key enzymes of citric acid cycle and gluconeogenesis were inhibited on administration of both alcohol and Toddy. Activity of glycolytic enzymes were increased. Toddy seemed to potentiate the toxicity induced by alcohol, indicating the additive effects of congeners.     

Stability analysis for bollworm complex in <Emphasis Type="Italic">Gossypium hirsutum</Emphasis> L.

One approach to improve cotton (Gossypium hirsutum L.) yield is to identify stable genotypes for low or no bollworms damage as it accounts low cost of cultivation to a considerable extent. The objective of the study was to identify stable genotypes for low bollworms damage under protected and unprotected experiments. Fifty cotton (Gossypium hirsutum L.) genotypes were evaluated for open bollworms damage percent (spotted, pink and Heliothis bollworms) for 3 years during 2003–2005 under protected and unprotected conditions. Variance due to genotypes, environments, genotype × environment and genotype × environment (linear) components were highly significant for the trait in protected and unprotected experiments. Under protected experiment, genotypes CSH 3020 and 3045 were found to be desirable and stable while genotype CSH 3058 was suited for poor environments. Fourteen genotypes viz. CSH 3034, 3035, 3043, 3044, 3047, 3051, 3053, 3058, 3059, 3094, 3106, 3114, 3123 and CSH-3157 were fairly stable under unprotected environments. The study lead to the conclude that in general for the two experiments the genotypes differed for stability for low bollworms damage.     

Phenotypic and RAPD diversity among Cymbopogon winterianus Jowitt accessions in relation to Cymbopogon nardus Rendle

The species Cymbopogon winterianus Jowitt is believed to have originated from the well-known species Cymbopogon nardus, type Maha Pengiri, referred to as Ceylonese (Sri Lankan) commercial citronella. Cymbopogon winterianus Jowitt was named after Winter, who raised its population as a separate species in the 19th century. C. winterianus was introduced into Indonesia and became commercially known as the Javanese citronella. The Javanese type C. winterianus material was introduced into India for the commercial cultivation of this crop during 1959. Varieties of this species have been developed later by the use of breeding procedures from the same introduced material. A comparative analysis of yields of herb, oil percentage and oil constituents for eight prevalent C. winterianus cultivars comparing them between themselves as well as against an accession of C. nardus has been carried out. All these accessions were analyzed at the molecular level for the similarity and genetic distances through RAPD profiling, using 20 random primers. More than 50% divergence was observed for all the C. winterianus accessions in relation to C. nardus accession CN2. The clustering based on the similarity matrices showed a major cluster of six accessions, consisting of two sub-clusters. The accession C. nardus CN2 got carved out along with two C. winterianus accessions, CW2 and CW6. On the other hand, the accessions CW2 and CW6 demonstrated distinct identities compared to CN2 at the DNA level.     

Energy Use and Output Assessment of Food-Forage Production Systems

An assessment of the energy requirements of different intensive forage production systems was carried out at the Indian Grassland Fodder, and Agroforestry Research Institute, Jhansi. This included assessment of energy use and output for five intensive crop production systems: (1) sorghum (single‐cut)–berseem, (2) cowpea–sorghum (single‐cut)–berseem + mustard–maize + cowpea, (3) sorghum (multi‐cut)–berseem + oats, (4) guar–oats–maize and (5) sorghum (single‐cut)–wheat–fallow. In all the systems, the Napier bajra hybrid (IGFRI‐3) was transplanted in regular plots of 50 m × 13 m. Results revealed that the total annual energy use was highest for sorghum (multi‐cut)–berseem + oats (36 606 MJ ha^?1), followed by sorghum (single‐cut)–berseem + mustard, sorghum (single‐cut)–berseem–cowpea, guar–oats–maize and sorghum (single‐cut)–wheat–fallow (for which values were 31 086, 30 449, 29 867 and 25 956 MJ energy ha^?1, respectively). The high value found for sorghum (multi‐cut)–berseem + oats might be attributable to the multi‐cuts in this system. Energy use by fertilizers represented the major part of the total energy use, amounting to 28–38 % in all treatments, followed by energy used in electricity, machinery, seeds, human labour and farmyard manure (FYM), in case of all with slight increase in input. In sorghum–wheat, energy use by seeds occupied the second position, followed by energy used in electricity, human labour, FYM and machinery/diesel. Pesticides contributed the least energy utilization in all the treatments. Herbicides were used for the control of weeds. Among the five forage production systems, sorghum (single‐cut)–berseem + mustard–maize + cowpea was found to be the most energy efficient, followed by sorghum (multi‐cut)–berseem + oats–sorghum (multi‐cut), sorghum (single‐cut)–berseem–cowpea, guar–oats–maize and sorghum (single‐cut)–wheat–fallow. Sorghum (single‐cut)–berseem + mustard–maize + cowpea increased the fertility of the soil, resulting in a higher percentage of organic carbon, higher availability of nitrogen and optimal balancing of the C:N ratio in the upper layers of the soil. These intensive crop production systems also maintain the optimum microbial population in the crop root zone. The benefit–cost ratio (B:C ratio) for the most energy‐efficient forage production system was 1.37 : 1. However, the highest B:C ratio was found in the sorghum–wheat rotation (1: 1.57).     

Influence of temperature on seed germination in papaya under subtropical conditions of India

The effect of temperature on germination and days taken for germination was evaluated in Carica papaya cvs., ‘Pune selection-3’ and ‘Pusa Dwarf’. The highest average seed germination per cent was observed in the month of July (96.8 and 93.0?%), followed by August (94 and 88.5?%), whereas the lowest average seed germination was observed in the month of January (44.2 and 36.8?%) in ‘Pune selection-3’ and ‘Pusa Dwarf’, respectively. Minimum number of days (5.17 and 6.33) was observed for germination in the month of July, whereas the maximum number of days (29.5 and 31) was taken in the month of January in both the cultivars, respectively. The average highest germination and seedling height was observed at temperature 29.8 °C and 29.5 °C during July and August, respectively, whereas the lowest was observed at temperature 14 °C and 15.9 °C during January and December, respectively. The optimum time for nursery sowing was July to August for autumn season crop under subtropical conditions of India.     

Loss of soil resources from water‐eroded versus uneroded cropland sites under simulated rainfall

Soil erosion is widespread in agricultural lands of the US Corn Belt. The objective of this study was to examine the impact of antecedent erosion on loss of soil under laboratory simulated rainfall. The soil was obtained from the surface layer of eroded (ER) and uneroded (UN) sites within a conservation agro‐ecosystem in central Ohio, USA. Air‐dried soil was subjected to a rainfall simulation for 60 min (dry run), and to another simulation (wet run) 24 h after the dry run. In the dry run, the cumulative water runoff, sediment yield, and soil organic carbon loss were higher in ER (12.3 L/m², 169.3 g/m², and 5.6 g/m², respectively) than in the UN (7.3 L/m², 22.6 g/m², and 0.9 g/m² respectively). An opposite trend was observed for the cumulative water infiltration (0.9 and 3.9 L/m², respectively). In the wet run, despite a similar cumulative water runoff from the two erosional phases (20.1 and 19.6 L/m² in ER and UN respectively), sediment yield and soil organic carbon loss were higher in ER (484.4 g/m², and 16.3 g/m² respectively) than in the UN (146.6 g/m², and 5.3 g/m² respectively). Also for the wet run, an opposite trend was observed for the cumulative infiltration (0.8 and 5.8 L/m² respectively). This study suggests that past erosional processes increase the susceptibility of remaining soil to accelerated erosion.     

Natural 13C abundance and soil carbon dynamics under long‐term residue retention in a no‐till maize system

Residue retention and reduced tillage are both conservation agricultural practices that may enhance soil organic carbon (SOC) stabilization in soil. We evaluated the long‐term effects of no‐till (NT) and stover retention from maize on SOC dynamics in a Rayne silt loam Typic Hapludults in Ohio. The six treatments consisted of retaining 0, 25, 50, 75, 100 and 200% of maize residues on each 3 × 3 m plot from the crop of previous year. Soil samples were obtained after 9 yrs of establishing the experiment. The whole soil (0–10 and 10–20 cm of soil depths) samples under different treatments were analysed for total C, total N, recalcitrant C (NaOCl treated sample) and ¹³C isotopic abundance (0–10 cm soil depth). Complete removal of stover for a period of 9 yrs significantly (P < 0.01) decreased soil C content (15.5 g/kg), whereas 200% of stover retention had the maximum soil C concentration (23.1 g/kg). Relative distribution of C for all the treatments in different fractions comprised of 55–58% as labile and 42–45% as recalcitrant. Retention of residue did not significantly affect total C and N concentration in 10–20 cm depth. ¹³C isotopic signature data indicated that C₄‐C (maize‐derived C) was the dominant fraction of C in the top 0–10 cm of soil layer under NT with maize‐derived C accounting for as high as 80% of the total SOC concentration. Contribution of C₄‐C or maize‐derived C was 71–84% in recalcitrant fraction in different residue retained plots. Residue management is imperative to increase SOC concentrations and long‐term agro‐ecosystem necessitates residue retention for stabilizing C in light‐textured soils.