Mapping cropland fallow areas in myanmar to scale up sustainable intensification of pulse crops in the farming system

Cropland fallows are the next best-bet for intensification and extensification, leading to increased food production and adding to the nutritional basket. The agronomical suitability of these lands can decide the extent of usage of these lands. Myanmar’s agricultural land (over 13.8 Mha) has the potential to expand by another 50% into additional fallow areas. These areas may be used to grow short-duration pulses, which are economically important and nutritionally rich, and constitute the diets of millions of people as well as provide an important source of livestock feed throughout Asia. Intensifying rice fallows will not only improve the productivity of the land but also increase the income of the smallholder farmers. The enhanced cultivation of pulses will help improve nutritional security in Myanmar and also help conserve natural resources and reduce environmental degradation. The objectives of this study was to use remote sensing methods to identify croplands in Myanmar and cropland fallow areas in two important agro-ecological regions, delta and coastal region and the dry zone. The study used moderate-resolution imaging spectroradiometer (MODIS) 250-m, 16-day normalized difference vegetation index (NDVI) maximum value composite (MVC), and land surface water index (LSWI) for one 1 year (1 June 2012–31 May 2013) along with seasonal field-plot level information and spectral matching techniques to derive croplands versus cropland fallows for each of the three seasons: the monsoon period between June and October; winter period between November and February; and summer period between March and May. The study showed that Myanmar had total net cropland area (TNCA) of 13.8 Mha. Cropland fallows during the monsoon season account for a meagre 2.4% of TNCA. However, in the winter season, 56.5% of TNCA (or 7.8 Mha) were classified as cropland fallows and during the summer season, 82.7% of TNCA (11.4 Mha) were cropland fallows. The producer’s accuracy of the cropland fallow class varied between 92 and 98% (errors of omission of 2 to 8%) and user’s accuracy varied between 82 and 92% (errors of commission of 8 to 18%) for winter and summer, respectively. Overall, the study estimated 19.2 Mha cropland fallows from the two major seasons (winter and summer). Out of this, 10.08 Mha has sufficient moisture (either from rainfall or stored soil water content) to grow short-season pulse crops. This potential with an estimated income of US$ 300 per hectare, if exploited sustainably, is estimated to bring an additional net income of about US$ 1.5 billion to Myanmar per year if at least half (5.04 Mha) of the total cropland fallows (10.08 Mha) is covered with short season pulses.     

Mapping rice-fallow cropland areas for short-season grain legumes intensification in South Asia using MODIS 250 m time-series data

The goal of this study was to map rainfed and irrigated rice-fallow cropland areas across South Asia, using MODIS 250?m time-series data and identify where the farming system may be intensified by the inclusion of a short-season crop during the fallow period. Rice-fallow cropland areas are those areas where rice is grown during the kharif growing season (June–October), followed by a fallow during the rabi season (November–February). These cropland areas are not suitable for growing rabi-season rice due to their high water needs, but are suitable for a short -season (≤3 months), low water-consuming grain legumes such as chickpea (Cicer arietinum L.), black gram, green gram, and lentils. Intensification (double-cropping) in this manner can improve smallholder farmer’s incomes and soil health via rich nitrogen-fixation legume crops as well as address food security challenges of ballooning populations without having to expand croplands. Several grain legumes, primarily chickpea, are increasingly grown across Asia as a source of income for smallholder farmers and at the same time providing rich and cheap source of protein that can improve the nutritional quality of diets in the region. The suitability of rainfed and irrigated rice-fallow croplands for grain legume cultivation across South Asia were defined by these identifiers: (a) rice crop is grown during the primary (kharif) crop growing season or during the north-west monsoon season (June–October); (b) same croplands are left fallow during the second (rabi) season or during the south-east monsoon season (November–February); and (c) ability to support low water-consuming, short-growing season (≤3 months) grain legumes (chickpea, black gram, green gram, and lentils) during rabi season. Existing irrigated or rainfed crops such as rice or wheat that were grown during kharif were not considered suitable for growing during the rabi season, because the moisture/water demand of these crops is too high. The study established cropland classes based on the every 16-day 250?m normalized difference vegetation index (NDVI) time series for one year (June 2010–May 2011) of Moderate Resolution Imaging Spectroradiometer (MODIS) data, using spectral matching techniques (SMTs), and extensive field knowledge. Map accuracy was evaluated based on independent ground survey data as well as compared with available sub-national level statistics. The producers’ and users’ accuracies of the cropland fallow classes were between 75% and 82%. The overall accuracy and the kappa coefficient estimated for rice classes were 82% and 0.79, respectively. The analysis estimated approximately 22.3?Mha of suitable rice-fallow areas in South Asia, with 88.3% in India, 0.5% in Pakistan, 1.1% in Sri Lanka, 8.7% in Bangladesh, 1.4% in Nepal, and 0.02% in Bhutan. Decision-makers can target these areas for sustainable intensification of short-duration grain legumes.     

Germination ofAcacia origena,A. pilispinaandPterolobium stellatumin response to different pre-sowing seed treatments, temperature and light

Seeds ofAcacia origena,A. pilispinaandPterolobium stellatumhave a hard seed coat that hampers imbibition of water and prevents maximum, uniform and rapid germination. Therefore, the seeds were subjected to different treatments involving mechanical scarification, concentrated sulphuric acid and boiling water to break the dormancy imposed by the hard seed coat. To determine the effects of different constant temperature regimes on germination, scarified seeds were incubated on a thermogradient at 10, 15, 20, 25 and 30°C. Germination of scarified seeds was also tested in light and dark. Mechanical scarification resulted in 100% germination for theAcaciaspecies and 94% forP. stellatum. ForA. origena, sulphuric acid treatments for 60, 90 and 120 min resulted in significantly higher per cent germination (>95%) than all the other treatments. ForA. pilispina, sulphuric acid treatments for 45 and 60 min, as well as immersing seeds for 1 min in hot water, gave significantly higher per cent germination (97%) than all the other treatments. ForP. stellatum, mechanical scarification and all the acid treatments applied resulted in significantly higher per cent germination (>85%) than the control and all hot water treatments. All seeds ofP. stellatumimmersed in hot water, even for 1 min, rotted soon after sowing, indicating that they are sensitive to high temperatures. Scarified seeds of the twoAcaciaspecies germinated to a higher degree (≥90%) between 10 and 30°C, while germination of scarified seeds ofP. stellatumranged from 48 to 82% between 10 and 30°C. Scarified seeds of the three species germinated to a large extent (>70%) both in light and dark, indicating that seeds do not require light for germination.     

Seed germination of seven Sahelian legume species

As part of the restoration of degraded land south of the Sahara, an experimental study has been carried out on the germinative properties of the seeds of seven Sahelian leguminous species (Cassia obtusifolia, Cassia occidentalis, Indigofera astragalina, Indigofera senegalensis, Indigofera tinctoria, Sesbania pachycarpa and Tephrosia purpurea). Analysis of the effects of temperature, pretreatment and water potential has enabled definition of their optimum germination conditions. For the temperature range studied (20–40°C), germination capacity was significantly greater between 30 and 35°C for all species. All species except Cassia obtusifolia developed a very strong integumental inhibition which was easily eliminated by mechanical scarification or immersion in concentrated sulphuric acid (H₂SO₄, 95%). Study of the influence of water potential on germination showed that these species are able to germinate at relatively low water potentials. Different patterns of response to water stress are highlighted and explained by the different behaviours of these species in the semi-arid conditions of the Sahelian environment.