Search

O trabalho teve o objetivo de verificar possiveis diferencas na acumulacao de massa seca, N, P, K, Ca, Mg e Zn entre duas cultivares de milho, BR 105 e BR 126, com e sem irrigacao suplementar por aspersao. Os tratamentos, dispostos em blocos, ao acaso, com duas repeticoes, foram constituidos por epocas de amostragem das plantas com 15, 35, 56, 78, 119 e 140 dias apos a germinacao. Para as respectivas analises quimicas e determinacao do peso seco, as plantas foram divididas em folhas, caules, palha, sabugo e graos. Constatou-se que ambas as cultivares apresentaram decrescimo de producao na ausencia de irrigacao suplementar. Nestas condicoes, a cultivar BR 105 apresentou decrescimo na translocacao de nutrientes para os graos, sem contudo, haver alteracoes quanto a producao de massa seca total. A cultivar BR126 apresentou decrescimo na producao de massa seca, alem da translocacao de nutrientes para os graos. Verificou-se, tambem, que a cultivar BR 105 e mais eficiente, pois, apresentou maior taxa de conversao dos nutrientes assimilados em graos do que a cultivar BR 126. A exportacao total de nutrientes seguiu a ordem decrescente: N (45-93 kg/ha) > K (12-25 kg/ha) > ou = P (11-20 kg/ha) > Mg (4-7 kg/ha) > Ca (0,2-0,6 kg/ha) > Zn (0,07 - 0,13 kg/ha). A producao de graos variou de 3.350 kg/ha a 6.500 kg/ha, respectivamente, para BR 126 sem irrigacao e BR 105 com irrigacao suplementar. Made available in DSpace on 2021-12-13T02:08:29Z (GMT). No. of bitstreams: 1 Acumulacao-massa.pdf: 8501994 bytes, checksum: e4adc7b76db808d2a9f7c8585b480c51 (MD5) Previous issue date: 1983

This article 'Variability in Daily Grain Production Per Hectare in Rice' appeared in the International Rice Research Newsletter series, created by the International Rice Research Institute (IRRI). The primary objective of this publication was to expedite communication among scientists concerned with the development of improved technology for rice and for rice based cropping systems. This publication will report what scientists are doing to increase the production of rice in as much as this crop feeds the most densely populated and land scarce nations in the world.

The Soviet Union consumes 218 million tons of grain a year but produces only about 180 million tons. The difference makes the Soviet Union the world's largest grain importer, accounting for almost 20 percent of international grain trade. This document presents a comprehensive data series on USSR grain yields, area, and production, including data by republics. It also includes a discussion of policies affecting Soviet grain output and an overview of the USDA process for making short-term forecasts of USSR grain production. Limitations of the data, especially as they affect the ability to forecast grain production, are emphasized.

China is becoming the largest grain producing and carbon-emitting country in the world, with a steady increase in population and economic development. A review of Chinese experiences in ensuring food self-sufficiency and reducing carbon emission in the agricultural sector can provide a valuable reference for similar countries and regions. According to a comprehensive review of previous publications and recent field observations, China has experienced on average a larger and faster climatic warming trend than the global trend, and there are large uncertainties in precipitation change, which shows a non-significantly increasing trend. Existing evidence shows that the effects of climatic warming on major staple crop production in China could be markedly negative or positive, depending on the specific cropping region, season, and crop. However, historical data analysis and field warming experiments have shown that moderate warming, of less than 2.0 °C, could benefit crop production in China overall. During the most recent warming decades, China has made successful adaptations in cropping systems, such as new cultivar breeding, cropping region adjustment, and cropping practice optimization, to exploit the positive rather than to avoid the negative effects of climatic warming on crop growth. All of these successful adaptations have greatly increased crop yield, leading to higher resource use efficiency as well as greatly increased soil organic carbon content with reduced greenhouse gas emissions. Under the warming climate, China has not only achieved great successes in crop production but also realized a large advance in greenhouse gas emission mitigation. Chinese experiences in cropping system innovation for coping with climatic warming demonstrate that food security and climatic warming mitigation can be synergized through policy, knowledge, and technological innovation. With the increasingly critical status of food security and climatic warming, further efforts should be invested in new agricultural policy, knowledge and technology creation, and popularization of climate-smart agriculture, and more financial investments should be made in field infrastructure development to increase cropping system resilience in China.

Основният подотрасъл на българското селско стопанство е зърнопроизводството. Повишаването на печалбите при отглеждането на зърнени култури е възможно чрез оптимизация на разходите. За да управляват ефективно стопанствата си зърнопроизводителите се съобразяват с особеностите на селското стопанство, като за да оптимизират своите производствени разходи, използват различни икономико-статистически методи. Целта на настоящата научна статия е да бъдат представени основните резултати от проведено пилотно анкетно изследване в хода на изпълнение на проект № 7-2010 „Оптимизирането на производствените разходи – предпоставка за устойчивост и конкурентоспособност в зърнопроизводството”. The main sub-sector of Bulgarian agriculture is grain production. The increase in profits in the cultivation of cereals is possible by optimization of costs. To effectively manage their farms grain producers take into account the specifics of agriculture, using various economic-statistical methods to optimize their production costs. The purpose of this article is to present the main results of a pilot questionnaire survey conducted during the implementation of the project № 7-2010 "Optimization of production costs - a prerequisite for sustainability and competitiveness in grain production”.