ABSTRACT
In the quest of achieving sustainable crop productivity, improved soil health, and increased carbon (C) sequestration in the soil, conservation agriculture (CA) is increasingly being promoted and adopted in the Indian subcontinent. However, because some researchers from different regions of the world have reported reduced crop yield under CA relative to agriculture based on conventional tillage (CT), a meta-analysis has been conducted based on published research from India to evaluate the effects of CA on the yield of crops, accumulation of soil organic C as an index of soil health, and C sequestration in the soil in different regions and soil textural groups in the country. The meta-analysis is based on 544 paired observations under CA and CT from 35 publications from India was carried out using Meta Win 2.1 software. The results showed an overall significant (p < 0.05) reduction of 1.15% crop yield under CA compared to CT. Yearwise data showed a reduction of yields under CA from 2009 to 2016, but an increase from 2017 to 2020. Yield reduction was observed in the eastern, north-eastern, and southern regions of India but in western, northern, and north-western regions of the country, an increase was observed under CA rather than CT. Sandy loam and clayey soils exhibited higher crop yield under CA than under CT. Compared to CT, soil organic C content and soil C sequestration under CA increased by 8.9% and 7.3%, respectively. Also, in all the regions and soil textural groups both soil organic C accumulation and soil C sequestration were higher under CA than under CT. Factors such as rainfall, soil depth, available nitrogen (N), and total N significantly influenced the extent of yield increase/decrease and soil organic C accumulation under CA. Overall, results of the meta-analysis suggest that the promotion of CA in India will have to be location-specific taking into consideration the crops, soil attributes, and climatic conditions.
Subject(s)
Agriculture , Carbon Sequestration , Conservation of Natural Resources , Crops, Agricultural , Soil , India , Soil/chemistry , Agriculture/methods , Carbon/analysisABSTRACT
The present experiment was conducted to assess the impact of fixed and variable doses (using a normalized difference vegetation index-sensor) of nitrogen (N) on wheat yields, nutrient uptake, nitrogen use efficiency, and soil nitrogen balance through the optimization of nitrogen dose. There were 10 treatments based on fixed and variable doses with different splits, and each treatment was replicated three times under a randomized complete block design. The treatments comprised fixed doses of 120 and 150 kg N ha-1 with different splits; variable doses based on sensor readings after application of 60, 90, and 120 kg N ha-1; 225 kg N ha-1 as a nitrogen-rich control; and no application of nitrogen as the absolute control. It was revealed that the application of a basal dose of 60 kg N ha-1 and another 60 kg N ha-1 at the crown root initiation stage followed by a sensor-guided N application significantly improved wheat grain yields and grain nitrogen uptake. However, straw nitrogen uptake was highest in N-rich plots where 225 kg N ha-1was applied. It was found that any curtailment in these doses at basal and crown root initiation stages followed by nitrogen application using a normalized difference vegetation index sensor later could not bring about higher crop yields. On average, wheat crops responded to 152-155 kg N ha-1 in both years of the study. Partial factor productivity along with agronomic and economic nitrogen use efficiency showed a declining trend with an increased rate of N application. Apparent N recovery values were comparable between normalized difference vegetation index sensor-based N application treatments and treatments receiving lesser N doses. Soil N status decreased in all the treatments except the nitrogen-rich strip, where there was a marginal increase in soil N status after the wheat crop harvest in the rotation. Partial nitrogen balance was negative for all the treatments except the control. From these 2-year field trials, it can be concluded that applying a normalized difference vegetation index sensor could be an essential tool for the rational management of fertilizer nitrogen in wheat grown in eastern sub-Himalayan plains.
ABSTRACT
The eastern sub-Himalayan plain of India is a popular potato growing belt in which vast scope exists to introduce processing grade cultivars. The selection and introduction of a better quality processing grade cultivar in this region may pave the way for the processing industries. Keeping these in the backdrop, this study was conducted at Instructional Farm of Uttar Banga Krishi Viswavidyalaya (UBKV), Pundibari, Cooch Behar, West Bengal, India under eastern sub-Himalayan plains during winter seasons of 2016-17 and 2017-18 in which seven processing type potato cultivars (Kufri Chipsona-1, Kufri Chipsona-3, Kufri Chipsona-4, Kufri Frysona, Kufri Himsona, Kufri Surya and Kufri Chandramukhi) were evaluated in terms of different quality parameters pre-requisite for chips processing viz., dry matter content, specific gravity, starch content, chips colour score, crispiness and hardness of chips through randomised complete block design (RCBD). The study revealed wide variation in all quality parameters amongst the cultivars. Cultivar 'Kufri Frysona' showed the highest specific gravity (1.121) as well as dry matter content (23.35%) followed by 'Kufri Chipsona-3'. The cultivar 'Kufri Frysona' showed the highest starch content (28.52%) too. Chips prepared from 'Kufri Chipsona-1' were recorded to be crispier with a relatively lower value of deformation before the first break and less hardness value. All processing type potato cultivar reflected the chips colour score <3 (evaluated, based on 1-10 scale, 10 being the darkest and least desirable) though 'Kufri Frysona' had the lowest chips colour score (1.50) signifying its superiority for the region. 'Kufri Frysona' cultivation could be recommended in this agro-climatic region particularly for chips manufacturing potato industries.